Zero-Knowledge Proofs & ZCash Simply Explained

d down, k up, everybody's a game theorist, titcoin, build wiki on Cardano, (e-)voting, competitive marketing analysis, Goguen product update, Alexa likes Charles, David hates all, Adam in and bros in arms with the scientific counterparts of the major cryptocurrency groups, the latest AMA for all!

Decreasing d parameter
Just signed the latest change management document, I was the last in the chain so I signed it today for changing the d parameter from 0.52 to 0.5. That means we are just about to cross the threshold here in a little bit for d to fall below 0.5 which means more than half of all the blocks will be made by the community and not the OBFT nodes. That's a major milestone and at this current rate of velocity it looks like d will decrement to zero around March so lots to do, lots to talk about. Product update, two days from now, we'll go ahead and talk about that but it crossed my desk today and I was really happy and excited about that and it seemed like yesterday that d was equal to one and people were complaining that we delayed it by an epoch and now we're almost at 50 percent. For those of you who want parameter-level changes, k-level changes, they are coming and there's an enormous internal conversation about it and we've written up a powerpoint presentation and a philosophy document about why things were designed the way that they're designed.
Increasing k parameter and upcoming security video and everybody's a game theorist
My chief scientist has put an enormous amount of time into this. Aggelos is very passionate about this particular topic and what I'm going to do is similar to the security video that I did where I did an hour and a half discussion about a best practice for security. I'm going to actually do a screencasted video where I talk about this philosophy document and I'm going to read the entire document with annotations with you guys and kind of talk through it. It might end up being quite a long video. It could be several hours long but I think it's really important to talk around the design philosophy of this. It's kind of funny, everybody, when they see a cryptographic paper or math paper, they tend to just say okay you guys figure that out. No one's an expert in cryptography or math and you don't really get strong opinions about it but game theory despite the fact that the topics as complex and in some cases more complex you tend to get a lot of opinions and everybody's a game theorist. So, there was enormous amount of thought that went into the design of the system, the parameters of system, everything from the reward functions to other things and it's very important that we explain that thought process in as detailed of a way as possible. At least the philosophy behind it then I feel that the community is in a really good position to start working on the change management. It is my position that I'd love to see k largely increased. I do think that the software needs some improvements to get there especially partial delegation delegation portfolios and some enhancements into the operation of staking especially.
E-voting
I'd love to see the existence of hybrid wallets where you have a cold part a hot part and we've had a lot of conversations about that and we will present some of the progress in that matter at the product updates. If not this October certainly in November. A lot of commercialization going along, a lot of things going on and flowing around and you know, commercial teams working hard. As I mentioned we have a lot of deals in the pipeline. The Wyoming event was half political, half sales. We were really looking into e-voting and we had very productive conversations along those lines. It is my goal that Cardano e-voting software is used in political primaries and my hope is for eventually to be used in municipal and state and eventually federal elections and then in national elections for countries like Ethiopia, Mongolia and other places. Now there is a long road, long, long road to get there and many little victories that have to begin but this event. Wyoming was kind of the opener into that conversation there were seven independent parties at the independent national convention and we had a chance to talk to the leadership of many of them. We will also engage in conversation with the libertarian party leadership as well and at the very least we could talk about e-voting and also blockchain-based voting for primaries that would be great start and we'll also look into the state of Wyoming for that as well. We'll you know, tell you guys about that in time. We've already gotten a lot of inquiries about e-voting software. We tend to get them along with the (Atala) Prism inquiries. It's actually quite easy to start conversations but there are a lot of security properties that are very important like end-to-end verifiability hybrid ballots where you have both a digital and a paper ballot delegation mechanics as well as privacy mechanics that are interesting on a case-by-case basis.
Goguen, voting, future fund3, competitive marketing analysis of Ouroboros vs. EOS, Tezos, Algorand, ETH2 and Polkadot, new creative director
We'll keep chipping away at that, a lot of Goguen stuff to talk about but I'm going to reserve all of that for two days from now for the product update. We're right in the middle, Goguen metadata was the very first part of it. We already have some commercialization platform as a result of metadata, more to come and then obviously lots of smart contract stuff to come. This update and the November update are going to be very Goguen focused and also a lot of alternatives as well. We're still on schedule for an HFC event in I think November or December. I can't remember but that's going to be carrying a lot of things related multisig token locking. There's some ledger rule changes so it has to be an HFC event and that opens up a lot of the windows for Goguen foundations as well as voting on chain so fund3 will benefit very heavily from that. We're right in the guts of Daedalus right now building the voting center, the identity center, QR-code work. All this stuff, it's a lot of stuff, you know, the cell phone app was released last week. Kind of an early beta, it'll go through a lot of rapid iterations every few weeks. We'll update it, google play is a great foundation to launch things on because it's so easy to push updates to people automatically so you can rapidly iterate and be very agile in that framework and you know we've already had 3500 people involved heavily in the innovation management platform ideascale and we've got numerous bids from everything. From John Buck and the sociocracy movement to others. A lot of people want to help us improve that and we're going to see steady and systematic growth there. We're still chipping away at product marketing. Liza (Horowitz) is doing a good job, meet with her two three-times a week and right now it's Ouroboros, Ouroboros, Ouroboros... We're doing competitive analysis of Ouroboros versus EOS, Tezos, Algorand, ETH2 and Polkadot. We think that's a good set. We think we have a really good way of explaining it. David (David Likes Crypto now at IOHK) has already made some great content. We're going to release that soon alongside some other content and we'll keep chipping away at that.
We also just hired a creative director for IO Global. His name's Adam, incredibly experienced creative director, he's worked for Mercedes-Benz and dozens of other companies. He does very good work and he's been doing this for well over 20 years and so the very first set of things he's going to do is work with commercial and marketing on product marketing. In addition to building great content where hope is make that content as pretty as possible and we have Rod heavily involved in that as well to talk about distribution channels and see if we can amplify the distribution message and really get a lot of stuff done. Last thing to mention, oh yeah, iOS for catalyst. We're working on that, we submitted it to the apple store, the iOS store, but it takes a little longer to get approval for that than it does with google play but that's been submitted and it's whenever apple approves it or not. Takes a little longer for cryptocurrency stuff.
Wiki shizzle and battle for crypto, make crypto articles on wiki great again, Alexa knows Charles, Everpedia meets Charles podcast, holy-grail land of Cardano, wiki on Cardano, titcoin
Wikipedia... kind of rattled the cage a little bit. Through an intermediary we got contact with Jimmy Wales. Larry Sanger, the other co-founder also reached out to me and the everpedia guys reached out to me. Here's where we stand, we have an article, it has solidified, it's currently labeled as unreliable and you should not believe the things that are said in it which is David Gerard's work if you look at the edits. We will work with the community and try to get that article to a fair and balanced representation of Cardano and especially after the product marketing comes through. We clearly explain the product I think the Cardano article can be massively strengthened. I've told Rod to work with some specialized people to try to get that done but we are going to work very hard at a systematic approval campaign for all of the scientific articles related to blockchain technology in the cryptocurrency space. They're just terrible, if you go to the proof of work article, the proof of stake or all these things, they're just terrible. They're not well written, they're out of date and they don't reflect an adequate sampling of the science. I did talk to my chief scientist Aggelos and what we're gonna do is reach out to the scientific counterparts that most of the major cryptocurrency groups that are doing research and see if they want to work with us at an industry-wide effort to systematically improve the scientific articles in our industry so that there are a fair and balanced representation of what the current state of the art are, the criticisms, the trade-offs as well as the reference space and of course obviously we'll do quite well in that respect because we've done the science. We're the inheritor of it but it's a shame because when people search proof of stake on google usually wikipedia results are highly biased. We care about wikipedia because google cares about wikipedia, amazon cares about wikipedia.
If you ask Alexa who is Charles Hoskinson, the reason why Alexa knows is because it's reading directly from the wikipedia page. If I didn't have a wikipedia page Alexa would know that so if somebody says Alexa what is Cardano it's going to read directly from the wikipedia page and you know and we can either just pretend that reality doesn't exist or we can accept it and we as a community working with partners in the broader cryptocurrency community can universally improve the quality of cryptocurrency pages. There's been a pattern of commercial censorship on wikipedia for cryptocurrencies in general since bitcoin itself. In fact I think the bitcoin article is actually taken down once back in, might have been, 2010 or 2009 but basically wikipedia has not been a friend of cryptocurrencies. That's why everpedia exists and actually their founders reached out to me and I talked to them over twitter through PMs and we agreed to actually do a podcast. I'm going to do a streamyard, stream with these guys and they'll come on talk all about everpedia and what they do and how they are and we'll kind of go through the challenges that they've encountered. How their platform works and so forth and obviously if they want to ever leave that terrible ecosystem EOS and come to the holy-grail land of Cardano we'd be there to help them out. At least they can tell the world how amazing their product is and also the challenges they're having to overcome. We've also been in great contact with Larry Sanger.
He's going to do an internal seminar at some point with with us and talk about some protocols he's been developing since he left wikipedia specifically to decentralize knowledge management and have a truly decentralized encyclopedia. I'm really looking forward to that and I hope that presentation gives us some inspiration as an ecosystem of things we can do. That's a great piece of infrastructure regardless and after we learn a lot more about it and we talk to a lot of people in ecosystem. If we can't get people to move on over, it would be really good to see through ideascale in the innovation management platform for people to utilize the dc fund to build their own variant of wikipedia on Cardano. In the coming months there will certainly be funding available. If you guys are so passionate about this particular problem that you want to go solve it then I'd be happy to play Elon Musk with the hyperloop and write a white paper on a protocol design and really give a good first start and then you guys can go and try to commercialize that technology as Cardano native assets and Plutus smart contracts in addition to other pieces of technology that have to be brought in to make it practical.
Right now we're just, let's talk to everybody phase, and we'll talk to the everpedia guys, we're going to talk to Larry and we're going to see whoever else is in this game and of course we have to accept the incumbency as it is. So, we're working with obviously the wikipedia side to improve the quality of not only our article but all of the articles and the scientific side of things so that there's a fair and accurate representation of information. One of the reasons why I'm so concerned about this is that I am very worried that Cardano projects will get commercially censored like we were commercially censored. So, yes we do have a page but it took five years to get there and we're a multi-billion dollar project with hundreds of thousands of people. If you guys are doing cutting-edge novel interesting stuff I don't want your experience to be the same as ours where you have to wait five years for your project to get a page even after government's adopted. That's absurd, no one should be censored ever. This is very well a fight for the entire ecosystem, the entire community, not just Cardano but all cryptocurrencies: bitcoin, ethereum and Cardano have all faced commercial censorship and article deletions during their tenure so I don't want you guys to go through that. I'm hoping we can prove that situation but you know you don't put all your eggs in one basket and frankly the time has come for wikipedia to be fully decentralized and liberated from a centralized organization and massively variable quality in the editor base. If legends of valor has a page but Cardano didn't have one until recently titcoin, a pornography coin from 2015, that's deprecated, no one uses it, has a page but Cardano couldn't get one there's something seriously wrong with the quality control mechanism and we need to improve that so it'll get done.
submitted by stake_pool to cardano [link] [comments]

Bob The Magic Custodian



Summary: Everyone knows that when you give your assets to someone else, they always keep them safe. If this is true for individuals, it is certainly true for businesses.
Custodians always tell the truth and manage funds properly. They won't have any interest in taking the assets as an exchange operator would. Auditors tell the truth and can't be misled. That's because organizations that are regulated are incapable of lying and don't make mistakes.

First, some background. Here is a summary of how custodians make us more secure:

Previously, we might give Alice our crypto assets to hold. There were risks:

But "no worries", Alice has a custodian named Bob. Bob is dressed in a nice suit. He knows some politicians. And he drives a Porsche. "So you have nothing to worry about!". And look at all the benefits we get:
See - all problems are solved! All we have to worry about now is:
It's pretty simple. Before we had to trust Alice. Now we only have to trust Alice, Bob, and all the ways in which they communicate. Just think of how much more secure we are!

"On top of that", Bob assures us, "we're using a special wallet structure". Bob shows Alice a diagram. "We've broken the balance up and store it in lots of smaller wallets. That way", he assures her, "a thief can't take it all at once". And he points to a historic case where a large sum was taken "because it was stored in a single wallet... how stupid".
"Very early on, we used to have all the crypto in one wallet", he said, "and then one Christmas a hacker came and took it all. We call him the Grinch. Now we individually wrap each crypto and stick it under a binary search tree. The Grinch has never been back since."

"As well", Bob continues, "even if someone were to get in, we've got insurance. It covers all thefts and even coercion, collusion, and misplaced keys - only subject to the policy terms and conditions." And with that, he pulls out a phone-book sized contract and slams it on the desk with a thud. "Yep", he continues, "we're paying top dollar for one of the best policies in the country!"
"Can I read it?' Alice asks. "Sure," Bob says, "just as soon as our legal team is done with it. They're almost through the first chapter." He pauses, then continues. "And can you believe that sales guy Mike? He has the same year Porsche as me. I mean, what are the odds?"

"Do you use multi-sig?", Alice asks. "Absolutely!" Bob replies. "All our engineers are fully trained in multi-sig. Whenever we want to set up a new wallet, we generate 2 separate keys in an air-gapped process and store them in this proprietary system here. Look, it even requires the biometric signature from one of our team members to initiate any withdrawal." He demonstrates by pressing his thumb into the display. "We use a third-party cloud validation API to match the thumbprint and authorize each withdrawal. The keys are also backed up daily to an off-site third-party."
"Wow that's really impressive," Alice says, "but what if we need access for a withdrawal outside of office hours?" "Well that's no issue", Bob says, "just send us an email, call, or text message and we always have someone on staff to help out. Just another part of our strong commitment to all our customers!"

"What about Proof of Reserve?", Alice asks. "Of course", Bob replies, "though rather than publish any blockchain addresses or signed transaction, for privacy we just do a SHA256 refactoring of the inverse hash modulus for each UTXO nonce and combine the smart contract coefficient consensus in our hyperledger lightning node. But it's really simple to use." He pushes a button and a large green checkmark appears on a screen. "See - the algorithm ran through and reserves are proven."
"Wow", Alice says, "you really know your stuff! And that is easy to use! What about fiat balances?" "Yeah, we have an auditor too", Bob replies, "Been using him for a long time so we have quite a strong relationship going! We have special books we give him every year and he's very efficient! Checks the fiat, crypto, and everything all at once!"

"We used to have a nice offline multi-sig setup we've been using without issue for the past 5 years, but I think we'll move all our funds over to your facility," Alice says. "Awesome", Bob replies, "Thanks so much! This is perfect timing too - my Porsche got a dent on it this morning. We have the paperwork right over here." "Great!", Alice replies.
And with that, Alice gets out her pen and Bob gets the contract. "Don't worry", he says, "you can take your crypto-assets back anytime you like - just subject to our cancellation policy. Our annual management fees are also super low and we don't adjust them often".

How many holes have to exist for your funds to get stolen?
Just one.

Why are we taking a powerful offline multi-sig setup, widely used globally in hundreds of different/lacking regulatory environments with 0 breaches to date, and circumventing it by a demonstrably weak third party layer? And paying a great expense to do so?
If you go through the list of breaches in the past 2 years to highly credible organizations, you go through the list of major corporate frauds (only the ones we know about), you go through the list of all the times platforms have lost funds, you go through the list of times and ways that people have lost their crypto from identity theft, hot wallet exploits, extortion, etc... and then you go through this custodian with a fine-tooth comb and truly believe they have value to add far beyond what you could, sticking your funds in a wallet (or set of wallets) they control exclusively is the absolute worst possible way to take advantage of that security.

The best way to add security for crypto-assets is to make a stronger multi-sig. With one custodian, what you are doing is giving them your cryptocurrency and hoping they're honest, competent, and flawlessly secure. It's no different than storing it on a really secure exchange. Maybe the insurance will cover you. Didn't work for Bitpay in 2015. Didn't work for Yapizon in 2017. Insurance has never paid a claim in the entire history of cryptocurrency. But maybe you'll get lucky. Maybe your exact scenario will buck the trend and be what they're willing to cover. After the large deductible and hopefully without a long and expensive court battle.

And you want to advertise this increase in risk, the lapse of judgement, an accident waiting to happen, as though it's some kind of benefit to customers ("Free institutional-grade storage for your digital assets.")? And then some people are writing to the OSC that custodians should be mandatory for all funds on every exchange platform? That this somehow will make Canadians as a whole more secure or better protected compared with standard air-gapped multi-sig? On what planet?

Most of the problems in Canada stemmed from one thing - a lack of transparency. If Canadians had known what a joke Quadriga was - it wouldn't have grown to lose $400m from hard-working Canadians from coast to coast to coast. And Gerald Cotten would be in jail, not wherever he is now (at best, rotting peacefully). EZ-BTC and mister Dave Smilie would have been a tiny little scam to his friends, not a multi-million dollar fraud. Einstein would have got their act together or been shut down BEFORE losing millions and millions more in people's funds generously donated to criminals. MapleChange wouldn't have even been a thing. And maybe we'd know a little more about CoinTradeNewNote - like how much was lost in there. Almost all of the major losses with cryptocurrency exchanges involve deception with unbacked funds.
So it's great to see transparency reports from BitBuy and ShakePay where someone independently verified the backing. The only thing we don't have is:
It's not complicated to validate cryptocurrency assets. They need to exist, they need to be spendable, and they need to cover the total balances. There are plenty of credible people and firms across the country that have the capacity to reasonably perform this validation. Having more frequent checks by different, independent, parties who publish transparent reports is far more valuable than an annual check by a single "more credible/official" party who does the exact same basic checks and may or may not publish anything. Here's an example set of requirements that could be mandated:
There are ways to structure audits such that neither crypto assets nor customer information are ever put at risk, and both can still be properly validated and publicly verifiable. There are also ways to structure audits such that they are completely reasonable for small platforms and don't inhibit innovation in any way. By making the process as reasonable as possible, we can completely eliminate any reason/excuse that an honest platform would have for not being audited. That is arguable far more important than any incremental improvement we might get from mandating "the best of the best" accountants. Right now we have nothing mandated and tons of Canadians using offshore exchanges with no oversight whatsoever.

Transparency does not prove crypto assets are safe. CoinTradeNewNote, Flexcoin ($600k), and Canadian Bitcoins ($100k) are examples where crypto-assets were breached from platforms in Canada. All of them were online wallets and used no multi-sig as far as any records show. This is consistent with what we see globally - air-gapped multi-sig wallets have an impeccable record, while other schemes tend to suffer breach after breach. We don't actually know how much CoinTrader lost because there was no visibility. Rather than publishing details of what happened, the co-founder of CoinTrader silently moved on to found another platform - the "most trusted way to buy and sell crypto" - a site that has no information whatsoever (that I could find) on the storage practices and a FAQ advising that “[t]rading cryptocurrency is completely safe” and that having your own wallet is “entirely up to you! You can certainly keep cryptocurrency, or fiat, or both, on the app.” Doesn't sound like much was learned here, which is really sad to see.
It's not that complicated or unreasonable to set up a proper hardware wallet. Multi-sig can be learned in a single course. Something the equivalent complexity of a driver's license test could prevent all the cold storage exploits we've seen to date - even globally. Platform operators have a key advantage in detecting and preventing fraud - they know their customers far better than any custodian ever would. The best job that custodians can do is to find high integrity individuals and train them to form even better wallet signatories. Rather than mandating that all platforms expose themselves to arbitrary third party risks, regulations should center around ensuring that all signatories are background-checked, properly trained, and using proper procedures. We also need to make sure that signatories are empowered with rights and responsibilities to reject and report fraud. They need to know that they can safely challenge and delay a transaction - even if it turns out they made a mistake. We need to have an environment where mistakes are brought to the surface and dealt with. Not one where firms and people feel the need to hide what happened. In addition to a knowledge-based test, an auditor can privately interview each signatory to make sure they're not in coercive situations, and we should make sure they can freely and anonymously report any issues without threat of retaliation.
A proper multi-sig has each signature held by a separate person and is governed by policies and mutual decisions instead of a hierarchy. It includes at least one redundant signature. For best results, 3of4, 3of5, 3of6, 4of5, 4of6, 4of7, 5of6, or 5of7.

History has demonstrated over and over again the risk of hot wallets even to highly credible organizations. Nonetheless, many platforms have hot wallets for convenience. While such losses are generally compensated by platforms without issue (for example Poloniex, Bitstamp, Bitfinex, Gatecoin, Coincheck, Bithumb, Zaif, CoinBene, Binance, Bitrue, Bitpoint, Upbit, VinDAX, and now KuCoin), the public tends to focus more on cases that didn't end well. Regardless of what systems are employed, there is always some level of risk. For that reason, most members of the public would prefer to see third party insurance.
Rather than trying to convince third party profit-seekers to provide comprehensive insurance and then relying on an expensive and slow legal system to enforce against whatever legal loopholes they manage to find each and every time something goes wrong, insurance could be run through multiple exchange operators and regulators, with the shared interest of having a reputable industry, keeping costs down, and taking care of Canadians. For example, a 4 of 7 multi-sig insurance fund held between 5 independent exchange operators and 2 regulatory bodies. All Canadian exchanges could pay premiums at a set rate based on their needed coverage, with a higher price paid for hot wallet coverage (anything not an air-gapped multi-sig cold wallet). Such a model would be much cheaper to manage, offer better coverage, and be much more reliable to payout when needed. The kind of coverage you could have under this model is unheard of. You could even create something like the CDIC to protect Canadians who get their trading accounts hacked if they can sufficiently prove the loss is legitimate. In cases of fraud, gross negligence, or insolvency, the fund can be used to pay affected users directly (utilizing the last transparent balance report in the worst case), something which private insurance would never touch. While it's recommended to have official policies for coverage, a model where members vote would fully cover edge cases. (Could be similar to the Supreme Court where justices vote based on case law.)
Such a model could fully protect all Canadians across all platforms. You can have a fiat coverage governed by legal agreements, and crypto-asset coverage governed by both multi-sig and legal agreements. It could be practical, affordable, and inclusive.

Now, we are at a crossroads. We can happily give up our freedom, our innovation, and our money. We can pay hefty expenses to auditors, lawyers, and regulators year after year (and make no mistake - this cost will grow to many millions or even billions as the industry grows - and it will be borne by all Canadians on every platform because platforms are not going to eat up these costs at a loss). We can make it nearly impossible for any new platform to enter the marketplace, forcing Canadians to use the same stagnant platforms year after year. We can centralize and consolidate the entire industry into 2 or 3 big players and have everyone else fail (possibly to heavy losses of users of those platforms). And when a flawed security model doesn't work and gets breached, we can make it even more complicated with even more people in suits making big money doing the job that blockchain was supposed to do in the first place. We can build a system which is so intertwined and dependent on big government, traditional finance, and central bankers that it's future depends entirely on that of the fiat system, of fractional banking, and of government bail-outs. If we choose this path, as history has shown us over and over again, we can not go back, save for revolution. Our children and grandchildren will still be paying the consequences of what we decided today.
Or, we can find solutions that work. We can maintain an open and innovative environment while making the adjustments we need to make to fully protect Canadian investors and cryptocurrency users, giving easy and affordable access to cryptocurrency for all Canadians on the platform of their choice, and creating an environment in which entrepreneurs and problem solvers can bring those solutions forward easily. None of the above precludes innovation in any way, or adds any unreasonable cost - and these three policies would demonstrably eliminate or resolve all 109 historic cases as studied here - that's every single case researched so far going back to 2011. It includes every loss that was studied so far not just in Canada but globally as well.
Unfortunately, finding answers is the least challenging part. Far more challenging is to get platform operators and regulators to agree on anything. My last post got no response whatsoever, and while the OSC has told me they're happy for industry feedback, I believe my opinion alone is fairly meaningless. This takes the whole community working together to solve. So please let me know your thoughts. Please take the time to upvote and share this with people. Please - let's get this solved and not leave it up to other people to do.

Facts/background/sources (skip if you like):



Thoughts?
submitted by azoundria2 to QuadrigaInitiative [link] [comments]

Syscoin Platform’s Great Reddit Scaling Bake-off Proposal

Syscoin Platform’s Great Reddit Scaling Bake-off Proposal

https://preview.redd.it/rqt2dldyg8e51.jpg?width=1044&format=pjpg&auto=webp&s=777ae9d4fbbb54c3540682b72700fc4ba3de0a44
We are excited to participate and present Syscoin Platform's ideal characteristics and capabilities towards a well-rounded Reddit Community Points solution!
Our scaling solution for Reddit Community Points involves 2-way peg interoperability with Ethereum. This will provide a scalable token layer built specifically for speed and high volumes of simple value transfers at a very low cost, while providing sovereign ownership and onchain finality.
Token transfers scale by taking advantage of a globally sorting mempool that provides for probabilistically secure assumptions of “as good as settled”. The opportunity here for token receivers is to have an app-layer interactivity on the speed/security tradeoff (99.9999% assurance within 10 seconds). We call this Z-DAG, and it achieves high-throughput across a mesh network topology presently composed of about 2,000 geographically dispersed full-nodes. Similar to Bitcoin, however, these nodes are incentivized to run full-nodes for the benefit of network security, through a bonded validator scheme. These nodes do not participate in the consensus of transactions or block validation any differently than other nodes and therefore do not degrade the security model of Bitcoin’s validate first then trust, across every node. Each token transfer settles on-chain. The protocol follows Bitcoin core policies so it has adequate code coverage and protocol hardening to be qualified as production quality software. It shares a significant portion of Bitcoin’s own hashpower through merged-mining.
This platform as a whole can serve token microtransactions, larger settlements, and store-of-value in an ideal fashion, providing probabilistic scalability whilst remaining decentralized according to Bitcoin design. It is accessible to ERC-20 via a permissionless and trust-minimized bridge that works in both directions. The bridge and token platform are currently available on the Syscoin mainnet. This has been gaining recent attention for use by loyalty point programs and stablecoins such as Binance USD.

Solutions

Syscoin Foundation identified a few paths for Reddit to leverage this infrastructure, each with trade-offs. The first provides the most cost-savings and scaling benefits at some sacrifice of token autonomy. The second offers more preservation of autonomy with a more narrow scope of cost savings than the first option, but savings even so. The third introduces more complexity than the previous two yet provides the most overall benefits. We consider the third as most viable as it enables Reddit to benefit even while retaining existing smart contract functionality. We will focus on the third option, and include the first two for good measure.
  1. Distribution, burns and user-to-user transfers of Reddit Points are entirely carried out on the Syscoin network. This full-on approach to utilizing the Syscoin network provides the most scalability and transaction cost benefits of these scenarios. The tradeoff here is distribution and subscription handling likely migrating away from smart contracts into the application layer.
  2. The Reddit Community Points ecosystem can continue to use existing smart contracts as they are used today on the Ethereum mainchain. Users migrate a portion of their tokens to Syscoin, the scaling network, to gain much lower fees, scalability, and a proven base layer, without sacrificing sovereign ownership. They would use Syscoin for user-to-user transfers. Tips redeemable in ten seconds or less, a high-throughput relay network, and onchain settlement at a block target of 60 seconds.
  3. Integration between Matic Network and Syscoin Platform - similar to Syscoin’s current integration with Ethereum - will provide Reddit Community Points with EVM scalability (including the Memberships ERC777 operator) on the Matic side, and performant simple value transfers, robust decentralized security, and sovereign store-of-value on the Syscoin side. It’s “the best of both worlds”. The trade-off is more complex interoperability.

Syscoin + Matic Integration

Matic and Blockchain Foundry Inc, the public company formed by the founders of Syscoin, recently entered a partnership for joint research and business development initiatives. This is ideal for all parties as Matic Network and Syscoin Platform provide complementary utility. Syscoin offers characteristics for sovereign ownership and security based on Bitcoin’s time-tested model, and shares a significant portion of Bitcoin’s own hashpower. Syscoin’s focus is on secure and scalable simple value transfers, trust-minimized interoperability, and opt-in regulatory compliance for tokenized assets rather than scalability for smart contract execution. On the other hand, Matic Network can provide scalable EVM for smart contract execution. Reddit Community Points can benefit from both.
Syscoin + Matic integration is actively being explored by both teams, as it is helpful to Reddit, Ethereum, and the industry as a whole.

Proving Performance & Cost Savings

Our POC focuses on 100,000 on-chain settlements of token transfers on the Syscoin Core blockchain. Transfers and burns perform equally with Syscoin. For POCs related to smart contracts (subscriptions, etc), refer to the Matic Network proposal.
On-chain settlement of 100k transactions was accomplished within roughly twelve minutes, well-exceeding Reddit’s expectation of five days. This was performed using six full-nodes operating on compute-optimized AWS c4.2xlarge instances which were geographically distributed (Virginia, London, Sao Paulo Brazil, Oregon, Singapore, Germany). A higher quantity of settlements could be reached within the same time-frame with more broadcasting nodes involved, or using hosts with more resources for faster execution of the process.
Addresses used: 100,014
The demonstration was executed using this tool. The results can be seen in the following blocks:
612722: https://sys1.bcfn.ca/block/6d47796d043bb4c508d29123e6ae81b051f5e0aaef849f253c8f3a6942a022ce
612723: https://sys1.bcfn.ca/block/8e2077f743461b90f80b4bef502f564933a8e04de97972901f3d65cfadcf1faf
612724: https://sys1.bcfn.ca/block/205436d25b1b499fce44c29567c5c807beaca915b83cc9f3c35b0d76dbb11f6e
612725: https://sys1.bcfn.ca/block/776d1b1a0f90f655a6bbdf559ff5072459cbdc5682d7615ff4b78c00babdc237
612726: https://sys1.bcfn.ca/block/de4df0994253742a1ac8ac9eec8d2a8c8b0a6d72c53d6f3caa29bb6c171b0a6b
612727: https://sys1.bcfn.ca/block/e5e167c52a9decb313fbaadf49a5e34cb490f8084f642a850385476d4ef10d70
612728: https://sys1.bcfn.ca/block/ab64d989edc71890e7b5b8491c20e9a27520dc45a5f7c776d3dae79057f59fe7
612729: https://sys1.bcfn.ca/block/5e8b7ecd0e36f99d07e4ea6e135fc952bf7ec30164ab6f4d1e98b0f2d405df6d
612730: https://sys1.bcfn.ca/block/d395df3d31dde60bbb0bece6bd5b358297da878f0beb96be389e5f0e043580a3
It is important to note that this POC is not focused on Z-DAG. The performance of Z-DAG has been benchmarked within realistic network conditions: Whiteblock’s audit is publicly available. Network latency tests showed an average TPS around 15k with burst capacity up to 61k. Zero-latency control group exhibited ~150k TPS. Mainnet testing of the Z-DAG network is achievable and will require further coordination and additional resources.
Even further optimizations are expected in the upcoming Syscoin Core release which will implement a UTXO model for our token layer bringing further efficiency as well as open the door to additional scaling technology currently under research by our team and academic partners. At present our token layer is account-based, similar to Ethereum. Opt-in compliance structures will also be introduced soon which will offer some positive performance characteristics as well. It makes the most sense to implement these optimizations before performing another benchmark for Z-DAG, especially on the mainnet considering the resources required to stress-test this network.

Cost Savings

Total cost for these 100k transactions: $0.63 USD
See the live fee comparison for savings estimation between transactions on Ethereum and Syscoin. Below is a snapshot at time of writing:
ETH price: $318.55 ETH gas price: 55.00 Gwei ($0.37)
Syscoin price: $0.11
Snapshot of live fee comparison chart
Z-DAG provides a more efficient fee-market. A typical Z-DAG transaction costs 0.0000582 SYS. Tokens can be safely redeemed/re-spent within seconds or allowed to settle on-chain beforehand. The costs should remain about this low for microtransactions.
Syscoin will achieve further reduction of fees and even greater scalability with offchain payment channels for assets, with Z-DAG as a resilience fallback. New payment channel technology is one of the topics under research by the Syscoin development team with our academic partners at TU Delft. In line with the calculation in the Lightning Networks white paper, payment channels using assets with Syscoin Core will bring theoretical capacity for each person on Earth (7.8 billion) to have five on-chain transactions per year, per person, without requiring anyone to enter a fee market (aka “wait for a block”). This exceeds the minimum LN expectation of two transactions per person, per year; one to exist on-chain and one to settle aggregated value.

Tools, Infrastructure & Documentation

Syscoin Bridge

Mainnet Demonstration of Syscoin Bridge with the Basic Attention Token ERC-20
A two-way blockchain interoperability system that uses Simple Payment Verification to enable:
  • Any Standard ERC-20 token to be moved from Ethereum to the Syscoin blockchain as a Syscoin Platform Token (SPT), and back to Ethereum
  • Any SPT to be moved from Syscoin to the Ethereum blockchain as an ERC-20 token, and back to Syscoin

Benefits

  • Permissionless
  • No counterparties involved
  • No trading mechanisms involved
  • No third-party liquidity providers required
  • Cross-chain Fractional Supply - 2-way peg - Token supply maintained globally
  • ERC-20s gain vastly improved transactionality with the Syscoin Token Platform, along with the security of bitcoin-core-compliant PoW.
  • SPTs gain access to all the tooling, applications and capabilities of Ethereum for ERC-20, including smart contracts.
https://preview.redd.it/l8t2m8ldh8e51.png?width=1180&format=png&auto=webp&s=b0a955a0181746dc79aff718bd0bf607d3c3aa23
https://preview.redd.it/26htnxzfh8e51.png?width=1180&format=png&auto=webp&s=d0383d3c2ee836c9f60b57eca35542e9545f741d

Source code

https://github.com/syscoin/?q=sysethereum
Main Subprojects

API

Tools to simplify using Syscoin Bridge as a service with dapps and wallets will be released some time after implementation of Syscoin Core 4.2. These will be based upon the same processes which are automated in the current live Sysethereum Dapp that is functioning with the Syscoin mainnet.

Documentation

Syscoin Bridge & How it Works (description and process flow)
Superblock Validation Battles
HOWTO: Provision the Bridge for your ERC-20
HOWTO: Setup an Agent
Developer & User Diligence

Trade-off

The Syscoin Ethereum Bridge is secured by Agent nodes participating in a decentralized and incentivized model that involves roles of Superblock challengers and submitters. This model is open to participation. The benefits here are trust-minimization, permissionless-ness, and potentially less legal/regulatory red-tape than interop mechanisms that involve liquidity providers and/or trading mechanisms.
The trade-off is that due to the decentralized nature there are cross-chain settlement times of one hour to cross from Ethereum to Syscoin, and three hours to cross from Syscoin to Ethereum. We are exploring ways to reduce this time while maintaining decentralization via zkp. Even so, an “instant bridge” experience could be provided by means of a third-party liquidity mechanism. That option exists but is not required for bridge functionality today. Typically bridges are used with batch value, not with high frequencies of smaller values, and generally it is advantageous to keep some value on both chains for maximum availability of utility. Even so, the cross-chain settlement time is good to mention here.

Cost

Ethereum -> Syscoin: Matic or Ethereum transaction fee for bridge contract interaction, negligible Syscoin transaction fee for minting tokens
Syscoin -> Ethereum: Negligible Syscoin transaction fee for burning tokens, 0.01% transaction fee paid to Bridge Agent in the form of the ERC-20, Matic or Ethereum transaction fee for contract interaction.

Z-DAG

Zero-Confirmation Directed Acyclic Graph is an instant settlement protocol that is used as a complementary system to proof-of-work (PoW) in the confirmation of Syscoin service transactions. In essence, a Z-DAG is simply a directed acyclic graph (DAG) where validating nodes verify the sequential ordering of transactions that are received in their memory pools. Z-DAG is used by the validating nodes across the network to ensure that there is absolute consensus on the ordering of transactions and no balances are overflowed (no double-spends).

Benefits

  • Unique fee-market that is more efficient for microtransaction redemption and settlement
  • Uses decentralized means to enable tokens with value transfer scalability that is comparable or exceeds that of credit card networks
  • Provides high throughput and secure fulfillment even if blocks are full
  • Probabilistic and interactive
  • 99.9999% security assurance within 10 seconds
  • Can serve payment channels as a resilience fallback that is faster and lower-cost than falling-back directly to a blockchain
  • Each Z-DAG transaction also settles onchain through Syscoin Core at 60-second block target using SHA-256 Proof of Work consensus
https://preview.redd.it/pgbx84jih8e51.png?width=1614&format=png&auto=webp&s=5f631d42a33dc698365eb8dd184b6d442def6640

Source code

https://github.com/syscoin/syscoin

API

Syscoin-js provides tooling for all Syscoin Core RPCs including interactivity with Z-DAG.

Documentation

Z-DAG White Paper
Useful read: An in-depth Z-DAG discussion between Syscoin Core developer Jag Sidhu and Brave Software Research Engineer Gonçalo Pestana

Trade-off

Z-DAG enables the ideal speed/security tradeoff to be determined per use-case in the application layer. It minimizes the sacrifice required to accept and redeem fast transfers/payments while providing more-than-ample security for microtransactions. This is supported on the premise that a Reddit user receiving points does need security yet generally doesn’t want nor need to wait for the same level of security as a nation-state settling an international trade debt. In any case, each Z-DAG transaction settles onchain at a block target of 60 seconds.

Syscoin Specs

Syscoin 3.0 White Paper
(4.0 white paper is pending. For improved scalability and less blockchain bloat, some features of v3 no longer exist in current v4: Specifically Marketplace Offers, Aliases, Escrow, Certificates, Pruning, Encrypted Messaging)
  • 16MB block bandwidth per minute assuming segwit witness carrying transactions, and transactions ~200 bytes on average
  • SHA256 merge mined with Bitcoin
  • UTXO asset layer, with base Syscoin layer sharing identical security policies as Bitcoin Core
  • Z-DAG on asset layer, bridge to Ethereum on asset layer
  • On-chain scaling with prospect of enabling enterprise grade reliable trustless payment processing with on/offchain hybrid solution
  • Focus only on Simple Value Transfers. MVP of blockchain consensus footprint is balances and ownership of them. Everything else can reduce data availability in exchange for scale (Ethereum 2.0 model). We leave that to other designs, we focus on transfers.
  • Future integrations of MAST/Taproot to get more complex value transfers without trading off trustlessness or decentralization.
  • Zero-knowledge Proofs are a cryptographic new frontier. We are dabbling here to generalize the concept of bridging and also verify the state of a chain efficiently. We also apply it in our Digital Identity projects at Blockchain Foundry (a publicly traded company which develops Syscoin softwares for clients). We are also looking to integrate privacy preserving payment channels for off-chain payments through zkSNARK hub & spoke design which does not suffer from the HTLC attack vectors evident on LN. Much of the issues plaguing Lightning Network can be resolved using a zkSNARK design whilst also providing the ability to do a multi-asset payment channel system. Currently we found a showstopper attack (American Call Option) on LN if we were to use multiple-assets. This would not exist in a system such as this.

Wallets

Web3 and mobile wallets are under active development by Blockchain Foundry Inc as WebAssembly applications and expected for release not long after mainnet deployment of Syscoin Core 4.2. Both of these will be multi-coin wallets that support Syscoin, SPTs, Ethereum, and ERC-20 tokens. The Web3 wallet will provide functionality similar to Metamask.
Syscoin Platform and tokens are already integrated with Blockbook. Custom hardware wallet support currently exists via ElectrumSys. First-class HW wallet integration through apps such as Ledger Live will exist after 4.2.
Current supported wallets
Syscoin Spark Desktop
Syscoin-Qt

Explorers

Mainnet: https://sys1.bcfn.ca (Blockbook)
Testnet: https://explorer-testnet.blockchainfoundry.co

Thank you for close consideration of our proposal. We look forward to feedback, and to working with the Reddit community to implement an ideal solution using Syscoin Platform!

submitted by sidhujag to ethereum [link] [comments]

RiB Newsletter #16 – Secure Enclaves à la Crab

For the last few months we’ve been following new zero-knowledge proof projects in Rust. This month, with Secret Network upgrading their mainnet with secret contracts, it seems like a good opportunity to explore Rust blockchains that are using a completely different privacy-preserving technology: secure enclaves.
Secure enclaves are processes whose environment is protected from inspection by other processes, even the kernel, by special hardware. This protection particularly involves the encryption of a process’s memory. Software that wants to compute in secret can put those computations inside a secure enclave and, if everything works as expected, neither a local user, nor the hosting provider, can snoop on the computations being performed. The most notable implementation of secure enclaves is Intel’s SGX (Secure Guard Extensions).
Secure enclaves are an attractive way to perform private computation primarily because they don’t impose any limitations on what can be computed — code that runs inside SGX is more-or-less just regular x86 code, just running inside a special environment. But depending on SGX for privacy does have some special risks: software that runs in an SGX enclave must be signed (if transitively) by Intel’s own cryptographic keys, which means that Intel must approve of any software running in SGX, that Intel can revoke permission to use SGX, and that there is a risk of the signing keys being compromised; and it’s not obvious that secure enclaves are actually secure, there have already been a number of attacks against SGX. Regardless, as of now, hardware enclaves provide security features that aren’t feasible any other way.
There are two prominent Rust blockchains relying on SGX:
Outside of the blockchain world there are some other Rust projects using SGX, the most notable being:
Whether it’s secure enclaves or zk-SNARKs, Rust blockchains are walking the bleeding edge of privacy tech.
In unrelated RiB news, we recently received two donations,
Thanks so much to our anonymous donors. We don’t often receive donations, so this was a nice surprise! We intend to put all monetary contributions to use funding events or new contributors, and we’ll let you know what we do with the funds when we spend them.

Project Spotlight

Each month we like to shine a light on a notable Rust blockchain project. This month that project is…
Aleo.
Aleo is a zero-knowledge blockchain, with its own zero-knowledge programming language, Leo.
We don’t have a lot to say about it, but we think it looks cool. We hope they blog more.

Interesting Things

News

Blog Posts

Papers

Projects


Read more: https://rustinblockchain.org/newsletters/2020-09-30-secure-enclaves-a-la-crab/
submitted by Aimeedeer to rust [link] [comments]

The Privacy Coin Guide Part 1

As interest picks up in crypto again, I want to share this post I made on privacy coins again to just give the basics of their evolution. This is only part 1, and parts 2 and 3 are not available in this format, but this part is informative and basic.
If you’re looking for a quick and easy way to assess what the best privacy coin in the current space is, which has the best features, or which is most likely to give high returns, then this is not that guide. My goal is to give you the power to make your own decisions, to clearly state my biases, and educate. I really wanted to understand this niche of the crypto-space due to my background and current loyalties[1], and grasp the nuances of the features, origins and timelines of technologies used in privacy coins, while not being anything close to a developer myself. This is going to be a 3-part series, starting with an overview and basic review of the technology, then looking at its implications, and ending with why I like a specific project. It might be mildly interesting or delightfully educational. Cryptocurrencies are young and existing privacy coins are deploying technology that is a work in progress. This series assumes a basic understanding of how blockchains work, specifically as used in cryptocurrencies. If you don’t have that understanding, might I suggest that you get it? [2],[3],[4] Because cryptocurrencies have a long way to go before reaching their end-game: when the world relies on the technology without understanding it. So, shall we do a deep dive into the privacy coin space?

FIRST THERE WAS BITCOIN

Cryptocurrencies allow you to tokenize value and track its exchange between hands over time, with transaction information verified by a distributed network of users. The most famous version of a cryptocurrency in use is Bitcoin, defined as peer-to-peer electronic cash. [5] Posted anonymously in 2008, the whitepaper seemed to be in direct response to the global financial meltdown and public distrust of the conventional banking and financing systems. Although cryptographic techniques are used in Bitcoin to ensure that (i) only the owner of a specific wallet has the authority to spend funds from that wallet, (ii) the public address is linked but cannot be traced by a third party to the private address (iii) the information is stored via cryptographic hashing in a merkle tree structure to ensure data integrity, the actual transaction information is publicly visible on the blockchain and can be traced back to the individual through chain analysis.[6] This has raised fears of possible financial censorship or the metaphorical tainting of money due to its origination point, as demonstrated in the Silk Road marketplace disaster.[7] This can happen because fiat money is usually exchanged for cryptocurrency at some point, as crypto-enthusiasts are born in the real world and inevitably cash out. There are already chain analysis firms and software that are increasingly efficient at tracking transactions on the Bitcoin blockchain.[8] This lack of privacy is one of the limitations of Bitcoin that has resulted in the creation of altcoins that experiment with the different features a cryptocurrency can have. Privacy coins are figuring out how to introduce privacy in addition to the payment network. The goal is to make the cryptocurrency fungible, each unit able to be exchanged for equal value without knowledge of its transaction history – like cash, while being publicly verifiable on a decentralized network. In other words, anyone can add the math up without being able to see the full details. Some privacy solutions and protocols have popped up as a result:

CRYPTONOTE – RING SIGNATURES AND STEALTH ADDRESSES

Used in: Monero and Particl as its successor RING-CT, Bytecoin
In December 2012, CryptoNote introduced the use of ring signatures and stealth addresses (along with other notable features such as its own codebase) to improve cryptocurrency privacy.[9] An updated CryptoNote version 2 came in October 2013 [10](though there is some dispute over this timeline [11]), also authored under the name Nicolas van Saberhagen. Ring signatures hide sender information by having the sender sign a transaction using a signature that could belong to multiple users. This makes a transaction untraceable. Stealth addresses allow a receiver to give a single address which generates a different public address for funds to be received at each time funds are sent to it. That makes a transaction unlinkable. In terms of privacy, CryptoNote gave us a protocol for untraceable and unlinkable transactions. The first implementation of CryptoNote technology was Bytecoin in March 2014 (timeline disputed [12]), which spawned many children (forks) in subsequent years, a notable example being Monero, based on CryptoNote v2 in April 2014.
RING SIGNATURES and STEALTH ADDRESSES

PROS

– Provides sender and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume
-Does not hide transaction information if not combined with another protocol.

COINJOIN

Used in: Dash
Bitcoin developer Gregory Maxwell proposed a set of solutions to bring privacy to Bitcoin and cryptocurrencies, the first being CoinJoin (January 28 – Aug 22, 2013).[13],[14] CoinJoin (sometimes called CoinSwap) allows multiple users to combine their transactions into a single transaction, by receiving inputs from multiple users, and then sending their outputs to the multiple users, irrespective of who in the group the inputs came from. So, the receiver will get whatever output amount they were supposed to, but it cannot be directly traced to its origination input. Similar proposals include Coinshuffle in 2014 and Tumblebit in 2016, building on CoinJoin but not terribly popular [15],[16]. They fixed the need for a trusted third party to ‘mix’ the transactions. There are CoinJoin implementations that are being actively worked on but are not the most popular privacy solutions of today. A notable coin that uses CoinJoin technology is Dash, launched in January 2014, with masternodes in place of a trusted party.
COINJOIN

PROS

– Provides sender and receiver privacy
– Easy to implement on any cryptocurrency
– Lightweight
– Greater scalability with bulletproofs
– Mature technology

CONS

– Least anonymous privacy solution. Transaction amounts can be calculated
– Even without third-party mixer, depends on wealth centralization of masternodes

ZEROCOIN

Used in: Zcoin, PIVX
In May 2013, the Zerocoin protocol was introduced by John Hopkins University professor Matthew D. Green and his graduate students Ian Miers and Christina Garman.[17] In response to the need for use of a third party to do CoinJoin, the Zerocoin proposal allowed for a coin to be destroyed and remade in order to erase its history whenever it is spent. Zero-knowledge cryptography and zero-knowledge proofs are used to prove that the new coins for spending are being appropriately made. A zero-knowledge proof allows one party to prove to another that they know specific information, without revealing any information about it, other than the fact that they know it. Zerocoin was not accepted by the Bitcoin community as an implementation to be added to Bitcoin, so a new cryptocurrency had to be formed. Zcoin was the first cryptocurrency to implement the Zerocoin protocol in 2016. [18]
ZEROCOIN

PROS

– Provides sender and receiver privacy
– Supply can be audited
– Relatively mature technology
– Does not require a third-party

CONS

– Requires trusted setup (May not be required with Sigma protocol)
– Large proof sizes (not lightweight)
– Does not provide full privacy for transaction amounts

ZEROCASH

Used in: Zcash, Horizen, Komodo, Zclassic, Bitcoin Private
In May 2014, the current successor to the Zerocoin protocol, Zerocash, was created, also by Matthew Green and others (Eli Ben-Sasson, Alessandro Chiesa, Christina Garman, Matthew Green, Ian Miers, Eran Tromer, Madars Virza).[19] It improved upon the Zerocoin concept by taking advantage of zero-knowledge proofs called zk-snarks (zero knowledge succinct non-interactive arguments of knowledge). Unlike Zerocoin, which hid coin origins and payment history, Zerocash was faster, with smaller transaction sizes, and hides transaction information on the sender, receiver and amount. Zcash is the first cryptocurrency to implement the Zerocash protocol in 2016. [20]
ZEROCASH

PROS

– Provides full anonymity. Sender, receiver and amount hidden.
– Privacy can be default?
– Fast due to small proof sizes.
– Payment amount can be optionally disclosed for auditing
– Does not require any third-party

CONS

– Requires trusted setup. (May be improved with zt-starks technology)
– Supply cannot be audited. And coins can potentially be forged without proper implementation.
– Private transactions computationally intensive (improved with Sapling upgrade)

CONFIDENTIAL TRANSACTIONS

Used in: Monero and Particl with Ring Signatures as RING-CT
The next proposal from Maxwell was that of confidential transactions, proposed in June 2015 as part of the Sidechain Elements project from Blockstream, where Maxwell was Chief Technical Officer.[21],[22] It proposed to hide the transaction amount and asset type (e.g. deposits, currencies, shares), so that only the sender and receiver are aware of the amount, unless they choose to make the amount public. It uses homomorphic encryption[23] to encrypt the inputs and outputs by using blinding factors and a kind of ring signature in a commitment scheme, so the amount can be ‘committed’ to, without the amount actually being known. I’m terribly sorry if you now have the urge to go and research exactly what that means. The takeaway is that the transaction amount can be hidden from outsiders while being verifiable.
CONFIDENTIAL TRANSACTIONS

PROS

– Hides transaction amounts
– Privacy can be default
– Mature technology
– Does not require any third-party

CONS

– Only provides transaction amount privacy when used alone

RING-CT

Used in: Monero, Particl
Then came Ring Confidential transactions, proposed by Shen-Noether of Monero Research Labs in October 2015.[24] RingCT combines the use of ring signatures for hiding sender information, with the use of confidential transactions (which also uses ring signatures) for hiding amounts. The proposal described a new type of ring signature, A Multi-layered Linkable Spontaneous Anonymous Group signature which “allows for hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation”.[25] RingCT was implemented in Monero in January 2017 and made mandatory after September 2017.
RING -CONFIDENTIAL TRANSACTIONS

PROS

– Provides full anonymity. Hides transaction amounts and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume

MIMBLEWIMBLE

Used in: Grin
Mimblewimble was proposed in July 2016 by pseudonymous contributor Tom Elvis Jedusorand further developed in October 2016 by Andrew Poelstra.[26],[27] Mimblewimble is a “privacy and fungibility focused cryptocoin transaction structure proposal”.[28] The key words are transaction structure proposal, so the way the blockchain is built is different, in order to accommodate privacy and fungibility features. Mimblewimble uses the concept of Confidential transactions to keep amounts hidden, looks at private keys and transaction information to prove ownership of funds rather than using addresses, and bundles transactions together instead of listing them separately on the blockchain. It also introduces a novel method of pruning the blockchain. Grin is a cryptocurrency in development that is applying Mimblewimble. Mimblewimble is early in development and you can understand it more here [29].
MIMBLEWIMBLE

PROS

– Hides transaction amounts and receiver privacy
– Privacy is on by default
– Lightweight
– No public addresses?

CONS

– Privacy not very effective without high volume
– Sender and receiver must both be online
– Relatively new technology

ZEXE

Fresh off the minds of brilliant cryptographers (Sean Bowe, Alessandro Chiesa, Matthew Green, Ian Miers, Pratyush Mishra, Howard Wu), in October 2018 Zexe proposed a new cryptographic primitive called ‘decentralized private computation.[30] It allows users of a decentralized ledger to “execute offline computations that result in transactions”[31], but also keeps transaction amounts hidden and allows transaction validation to happen at any time regardless of computations being done online. This can have far reaching implications for privacy coins in the future. Consider cases where transactions need to be automatic and private, without both parties being present.

NETWORK PRIVACY

Privacy technologies that look at network privacy as nodes communicate with each other on the network are important considerations, rather than just looking at privacy on the blockchain itself. Anonymous layers encrypt and/or reroute data as it moves among peers, so it is not obvious who they originate from on the network. They are used to protect against surveillance or censorship from ISPs and governments. The Invisible Internet Project (I2P) is an anonymous network layer that uses end to end encryption for peers on a network to communicate with each other.[32] Its history dates back to 2003. Kovri is a Monero created implementation of I2P.[33] The Onion Router (Tor) is another anonymity layer [34]) that Verge is a privacy cryptocurrency that uses. But its historical link to the US government may be is concerning to some[35]. Dandelion transaction relay is also an upcoming Bitcoin improvement proposal (BIP) that scrambles IP data that will provide network privacy for Bitcoin as transaction and other information is transmitted.[36],[37],[38]

UPCOMING

Monero completed bulletproofs protocol updates that reduce RINGCT transaction sizes and thus transaction fee costs. (Bulletproofs are a replacement for range proofs used in confidential transactions that aid in encrypting inputs and outputs by making sure they add to zero).
Sigma Protocol – being actively researched by Zcoin team as of 2018 to replace Zerocoin protocol so that a trusted setup is not required.[39] There is a possible replacement for zk-snarks, called zk-starks, another form of zero-knowledge proof technology, that may make a trusted set-up unnecessary for zero-knowledege proof coins.[40]

PART 1 CONCLUSION OF THE PRIVACY COIN GUIDE ON THE TECHNOLOGY BEHIND PRIVACY COINS

Although Bitcoin is still a groundbreaking technology that gives us a trust-less transaction system, it has failed to live up to its expectations of privacy. Over time, new privacy technologies have arrived and are arriving with innovative and exciting solutions for Bitcoin’s lack of fungibility. It is important to note that these technologies are built on prior research and application, but we are considering their use in cryptocurrencies. Protocols are proposed based on cryptographic concepts that show how they would work, and then developers actually implement them. Please note that I did not include the possibility of improper implementation as a disadvantage, and the advantages assume that the technical development is well done. A very important point is that coins can also adapt new privacy technologies as their merits become obvious, even as they start with a specific privacy protocol. Furthermore, I am, unfortunately, positive that this is not an exhaustive overview and I am only covering publicized solutions. Next, we’ll talk more about the pros and cons and give an idea of how the coins can be compared.

There's a video version that can be watched, and you can find out how to get the second two parts if you want on my website (video link on the page): https://cryptoramble.com/guide-on-privacy-coins/
submitted by CryptoRamble to ethereum [link] [comments]

The Privacy Coin Guide Part 1

As interest picks up in crypto again, I want to share this post I made on privacy coins again to just give the basics of their evolution. This is only part 1, and parts 2 and 3 are not available in this format, but this part is informative and basic.
If you’re looking for a quick and easy way to assess what the best privacy coin in the current space is, which has the best features, or which is most likely to give high returns, then this is not that guide. My goal is to give you the power to make your own decisions, to clearly state my biases, and educate. I really wanted to understand this niche of the crypto-space due to my background and current loyalties[1], and grasp the nuances of the features, origins and timelines of technologies used in privacy coins, while not being anything close to a developer myself. This is going to be a 3-part series, starting with an overview and basic review of the technology, then looking at its implications, and ending with why I like a specific project. It might be mildly interesting or delightfully educational. Cryptocurrencies are young and existing privacy coins are deploying technology that is a work in progress. This series assumes a basic understanding of how blockchains work, specifically as used in cryptocurrencies. If you don’t have that understanding, might I suggest that you get it? [2],[3],[4] Because cryptocurrencies have a long way to go before reaching their end-game: when the world relies on the technology without understanding it. So, shall we do a deep dive into the privacy coin space?

FIRST THERE WAS BITCOIN

Cryptocurrencies allow you to tokenize value and track its exchange between hands over time, with transaction information verified by a distributed network of users. The most famous version of a cryptocurrency in use is Bitcoin, defined as peer-to-peer electronic cash. [5] Posted anonymously in 2008, the whitepaper seemed to be in direct response to the global financial meltdown and public distrust of the conventional banking and financing systems. Although cryptographic techniques are used in Bitcoin to ensure that (i) only the owner of a specific wallet has the authority to spend funds from that wallet, (ii) the public address is linked but cannot be traced by a third party to the private address (iii) the information is stored via cryptographic hashing in a merkle tree structure to ensure data integrity, the actual transaction information is publicly visible on the blockchain and can be traced back to the individual through chain analysis.[6] This has raised fears of possible financial censorship or the metaphorical tainting of money due to its origination point, as demonstrated in the Silk Road marketplace disaster.[7] This can happen because fiat money is usually exchanged for cryptocurrency at some point, as crypto-enthusiasts are born in the real world and inevitably cash out. There are already chain analysis firms and software that are increasingly efficient at tracking transactions on the Bitcoin blockchain.[8] This lack of privacy is one of the limitations of Bitcoin that has resulted in the creation of altcoins that experiment with the different features a cryptocurrency can have. Privacy coins are figuring out how to introduce privacy in addition to the payment network. The goal is to make the cryptocurrency fungible, each unit able to be exchanged for equal value without knowledge of its transaction history – like cash, while being publicly verifiable on a decentralized network. In other words, anyone can add the math up without being able to see the full details. Some privacy solutions and protocols have popped up as a result:

CRYPTONOTE – RING SIGNATURES AND STEALTH ADDRESSES

Used in: Monero and Particl as its successor RING-CT, Bytecoin
In December 2012, CryptoNote introduced the use of ring signatures and stealth addresses (along with other notable features such as its own codebase) to improve cryptocurrency privacy.[9] An updated CryptoNote version 2 came in October 2013 [10](though there is some dispute over this timeline [11]), also authored under the name Nicolas van Saberhagen. Ring signatures hide sender information by having the sender sign a transaction using a signature that could belong to multiple users. This makes a transaction untraceable. Stealth addresses allow a receiver to give a single address which generates a different public address for funds to be received at each time funds are sent to it. That makes a transaction unlinkable. In terms of privacy, CryptoNote gave us a protocol for untraceable and unlinkable transactions. The first implementation of CryptoNote technology was Bytecoin in March 2014 (timeline disputed [12]), which spawned many children (forks) in subsequent years, a notable example being Monero, based on CryptoNote v2 in April 2014.
RING SIGNATURES and STEALTH ADDRESSES

PROS

– Provides sender and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume
-Does not hide transaction information if not combined with another protocol.

COINJOIN

Used in: Dash
Bitcoin developer Gregory Maxwell proposed a set of solutions to bring privacy to Bitcoin and cryptocurrencies, the first being CoinJoin (January 28 – Aug 22, 2013).[13],[14] CoinJoin (sometimes called CoinSwap) allows multiple users to combine their transactions into a single transaction, by receiving inputs from multiple users, and then sending their outputs to the multiple users, irrespective of who in the group the inputs came from. So, the receiver will get whatever output amount they were supposed to, but it cannot be directly traced to its origination input. Similar proposals include Coinshuffle in 2014 and Tumblebit in 2016, building on CoinJoin but not terribly popular [15],[16]. They fixed the need for a trusted third party to ‘mix’ the transactions. There are CoinJoin implementations that are being actively worked on but are not the most popular privacy solutions of today. A notable coin that uses CoinJoin technology is Dash, launched in January 2014, with masternodes in place of a trusted party.
COINJOIN

PROS

– Provides sender and receiver privacy
– Easy to implement on any cryptocurrency
– Lightweight
– Greater scalability with bulletproofs
– Mature technology

CONS

– Least anonymous privacy solution. Transaction amounts can be calculated
– Even without third-party mixer, depends on wealth centralization of masternodes

ZEROCOIN

Used in: Zcoin, PIVX
In May 2013, the Zerocoin protocol was introduced by John Hopkins University professor Matthew D. Green and his graduate students Ian Miers and Christina Garman.[17] In response to the need for use of a third party to do CoinJoin, the Zerocoin proposal allowed for a coin to be destroyed and remade in order to erase its history whenever it is spent. Zero-knowledge cryptography and zero-knowledge proofs are used to prove that the new coins for spending are being appropriately made. A zero-knowledge proof allows one party to prove to another that they know specific information, without revealing any information about it, other than the fact that they know it. Zerocoin was not accepted by the Bitcoin community as an implementation to be added to Bitcoin, so a new cryptocurrency had to be formed. Zcoin was the first cryptocurrency to implement the Zerocoin protocol in 2016. [18]
ZEROCOIN

PROS

– Provides sender and receiver privacy
– Supply can be audited
– Relatively mature technology
– Does not require a third-party

CONS

– Requires trusted setup (May not be required with Sigma protocol)
– Large proof sizes (not lightweight)
– Does not provide full privacy for transaction amounts

ZEROCASH

Used in: Zcash, Horizen, Komodo, Zclassic, Bitcoin Private
In May 2014, the current successor to the Zerocoin protocol, Zerocash, was created, also by Matthew Green and others (Eli Ben-Sasson, Alessandro Chiesa, Christina Garman, Matthew Green, Ian Miers, Eran Tromer, Madars Virza).[19] It improved upon the Zerocoin concept by taking advantage of zero-knowledge proofs called zk-snarks (zero knowledge succinct non-interactive arguments of knowledge). Unlike Zerocoin, which hid coin origins and payment history, Zerocash was faster, with smaller transaction sizes, and hides transaction information on the sender, receiver and amount. Zcash is the first cryptocurrency to implement the Zerocash protocol in 2016. [20]
ZEROCASH

PROS

– Provides full anonymity. Sender, receiver and amount hidden.
– Privacy can be default?
– Fast due to small proof sizes.
– Payment amount can be optionally disclosed for auditing
– Does not require any third-party

CONS

– Requires trusted setup. (May be improved with zt-starks technology)
– Supply cannot be audited. And coins can potentially be forged without proper implementation.
– Private transactions computationally intensive (improved with Sapling upgrade)

CONFIDENTIAL TRANSACTIONS

Used in: Monero and Particl with Ring Signatures as RING-CT
The next proposal from Maxwell was that of confidential transactions, proposed in June 2015 as part of the Sidechain Elements project from Blockstream, where Maxwell was Chief Technical Officer.[21],[22] It proposed to hide the transaction amount and asset type (e.g. deposits, currencies, shares), so that only the sender and receiver are aware of the amount, unless they choose to make the amount public. It uses homomorphic encryption[23] to encrypt the inputs and outputs by using blinding factors and a kind of ring signature in a commitment scheme, so the amount can be ‘committed’ to, without the amount actually being known. I’m terribly sorry if you now have the urge to go and research exactly what that means. The takeaway is that the transaction amount can be hidden from outsiders while being verifiable.
CONFIDENTIAL TRANSACTIONS

PROS

– Hides transaction amounts
– Privacy can be default
– Mature technology
– Does not require any third-party

CONS

– Only provides transaction amount privacy when used alone

RING-CT

Used in: Monero, Particl
Then came Ring Confidential transactions, proposed by Shen-Noether of Monero Research Labs in October 2015.[24] RingCT combines the use of ring signatures for hiding sender information, with the use of confidential transactions (which also uses ring signatures) for hiding amounts. The proposal described a new type of ring signature, A Multi-layered Linkable Spontaneous Anonymous Group signature which “allows for hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation”.[25] RingCT was implemented in Monero in January 2017 and made mandatory after September 2017.
RING -CONFIDENTIAL TRANSACTIONS

PROS

– Provides full anonymity. Hides transaction amounts and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume

MIMBLEWIMBLE

Used in: Grin
Mimblewimble was proposed in July 2016 by pseudonymous contributor Tom Elvis Jedusorand further developed in October 2016 by Andrew Poelstra.[26],[27] Mimblewimble is a “privacy and fungibility focused cryptocoin transaction structure proposal”.[28] The key words are transaction structure proposal, so the way the blockchain is built is different, in order to accommodate privacy and fungibility features. Mimblewimble uses the concept of Confidential transactions to keep amounts hidden, looks at private keys and transaction information to prove ownership of funds rather than using addresses, and bundles transactions together instead of listing them separately on the blockchain. It also introduces a novel method of pruning the blockchain. Grin is a cryptocurrency in development that is applying Mimblewimble. Mimblewimble is early in development and you can understand it more here [29].
MIMBLEWIMBLE

PROS

– Hides transaction amounts and receiver privacy
– Privacy is on by default
– Lightweight
– No public addresses?

CONS

– Privacy not very effective without high volume
– Sender and receiver must both be online
– Relatively new technology

ZEXE

Fresh off the minds of brilliant cryptographers (Sean Bowe, Alessandro Chiesa, Matthew Green, Ian Miers, Pratyush Mishra, Howard Wu), in October 2018 Zexe proposed a new cryptographic primitive called ‘decentralized private computation.[30] It allows users of a decentralized ledger to “execute offline computations that result in transactions”[31], but also keeps transaction amounts hidden and allows transaction validation to happen at any time regardless of computations being done online. This can have far reaching implications for privacy coins in the future. Consider cases where transactions need to be automatic and private, without both parties being present.

NETWORK PRIVACY

Privacy technologies that look at network privacy as nodes communicate with each other on the network are important considerations, rather than just looking at privacy on the blockchain itself. Anonymous layers encrypt and/or reroute data as it moves among peers, so it is not obvious who they originate from on the network. They are used to protect against surveillance or censorship from ISPs and governments. The Invisible Internet Project (I2P) is an anonymous network layer that uses end to end encryption for peers on a network to communicate with each other.[32] Its history dates back to 2003. Kovri is a Monero created implementation of I2P.[33] The Onion Router (Tor) is another anonymity layer [34]) that Verge is a privacy cryptocurrency that uses. But its historical link to the US government may be is concerning to some[35]. Dandelion transaction relay is also an upcoming Bitcoin improvement proposal (BIP) that scrambles IP data that will provide network privacy for Bitcoin as transaction and other information is transmitted.[36],[37],[38]

UPCOMING

Monero completed bulletproofs protocol updates that reduce RINGCT transaction sizes and thus transaction fee costs. (Bulletproofs are a replacement for range proofs used in confidential transactions that aid in encrypting inputs and outputs by making sure they add to zero).
Sigma Protocol – being actively researched by Zcoin team as of 2018 to replace Zerocoin protocol so that a trusted setup is not required.[39] There is a possible replacement for zk-snarks, called zk-starks, another form of zero-knowledge proof technology, that may make a trusted set-up unnecessary for zero-knowledege proof coins.[40]

PART 1 CONCLUSION OF THE PRIVACY COIN GUIDE ON THE TECHNOLOGY BEHIND PRIVACY COINS

Although Bitcoin is still a groundbreaking technology that gives us a trust-less transaction system, it has failed to live up to its expectations of privacy. Over time, new privacy technologies have arrived and are arriving with innovative and exciting solutions for Bitcoin’s lack of fungibility. It is important to note that these technologies are built on prior research and application, but we are considering their use in cryptocurrencies. Protocols are proposed based on cryptographic concepts that show how they would work, and then developers actually implement them. Please note that I did not include the possibility of improper implementation as a disadvantage, and the advantages assume that the technical development is well done. A very important point is that coins can also adapt new privacy technologies as their merits become obvious, even as they start with a specific privacy protocol. Furthermore, I am, unfortunately, positive that this is not an exhaustive overview and I am only covering publicized solutions. Next, we’ll talk more about the pros and cons and give an idea of how the coins can be compared.

There's a video version that can be watched, and you can find out how to get the second two parts if you want on my website (video link on the page): https://cryptoramble.com/guide-on-privacy-coins/
submitted by CryptoRamble to privacycoins [link] [comments]

The Privacy Coin Guide Part 1

As interest picks up in crypto again, I want to share this post I made on privacy coins again to just give the basics of their evolution. This is only part 1, and parts 2 and 3 are not available in this format, but this part is informative and basic.
If you’re looking for a quick and easy way to assess what the best privacy coin in the current space is, which has the best features, or which is most likely to give high returns, then this is not that guide. My goal is to give you the power to make your own decisions, to clearly state my biases, and educate. I really wanted to understand this niche of the crypto-space due to my background and current loyalties[1], and grasp the nuances of the features, origins and timelines of technologies used in privacy coins, while not being anything close to a developer myself. This is going to be a 3-part series, starting with an overview and basic review of the technology, then looking at its implications, and ending with why I like a specific project. It might be mildly interesting or delightfully educational. Cryptocurrencies are young and existing privacy coins are deploying technology that is a work in progress. This series assumes a basic understanding of how blockchains work, specifically as used in cryptocurrencies. If you don’t have that understanding, might I suggest that you get it? [2],[3],[4] Because cryptocurrencies have a long way to go before reaching their end-game: when the world relies on the technology without understanding it. So, shall we do a deep dive into the privacy coin space?

FIRST THERE WAS BITCOIN

Cryptocurrencies allow you to tokenize value and track its exchange between hands over time, with transaction information verified by a distributed network of users. The most famous version of a cryptocurrency in use is Bitcoin, defined as peer-to-peer electronic cash. [5] Posted anonymously in 2008, the whitepaper seemed to be in direct response to the global financial meltdown and public distrust of the conventional banking and financing systems. Although cryptographic techniques are used in Bitcoin to ensure that (i) only the owner of a specific wallet has the authority to spend funds from that wallet, (ii) the public address is linked but cannot be traced by a third party to the private address (iii) the information is stored via cryptographic hashing in a merkle tree structure to ensure data integrity, the actual transaction information is publicly visible on the blockchain and can be traced back to the individual through chain analysis.[6] This has raised fears of possible financial censorship or the metaphorical tainting of money due to its origination point, as demonstrated in the Silk Road marketplace disaster.[7] This can happen because fiat money is usually exchanged for cryptocurrency at some point, as crypto-enthusiasts are born in the real world and inevitably cash out. There are already chain analysis firms and software that are increasingly efficient at tracking transactions on the Bitcoin blockchain.[8] This lack of privacy is one of the limitations of Bitcoin that has resulted in the creation of altcoins that experiment with the different features a cryptocurrency can have. Privacy coins are figuring out how to introduce privacy in addition to the payment network. The goal is to make the cryptocurrency fungible, each unit able to be exchanged for equal value without knowledge of its transaction history – like cash, while being publicly verifiable on a decentralized network. In other words, anyone can add the math up without being able to see the full details. Some privacy solutions and protocols have popped up as a result:

CRYPTONOTE – RING SIGNATURES AND STEALTH ADDRESSES

Used in: Monero and Particl as its successor RING-CT, Bytecoin
In December 2012, CryptoNote introduced the use of ring signatures and stealth addresses (along with other notable features such as its own codebase) to improve cryptocurrency privacy.[9] An updated CryptoNote version 2 came in October 2013 [10](though there is some dispute over this timeline [11]), also authored under the name Nicolas van Saberhagen. Ring signatures hide sender information by having the sender sign a transaction using a signature that could belong to multiple users. This makes a transaction untraceable. Stealth addresses allow a receiver to give a single address which generates a different public address for funds to be received at each time funds are sent to it. That makes a transaction unlinkable. In terms of privacy, CryptoNote gave us a protocol for untraceable and unlinkable transactions. The first implementation of CryptoNote technology was Bytecoin in March 2014 (timeline disputed [12]), which spawned many children (forks) in subsequent years, a notable example being Monero, based on CryptoNote v2 in April 2014.
RING SIGNATURES and STEALTH ADDRESSES

PROS

– Provides sender and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume
-Does not hide transaction information if not combined with another protocol.

COINJOIN

Used in: Dash
Bitcoin developer Gregory Maxwell proposed a set of solutions to bring privacy to Bitcoin and cryptocurrencies, the first being CoinJoin (January 28 – Aug 22, 2013).[13],[14] CoinJoin (sometimes called CoinSwap) allows multiple users to combine their transactions into a single transaction, by receiving inputs from multiple users, and then sending their outputs to the multiple users, irrespective of who in the group the inputs came from. So, the receiver will get whatever output amount they were supposed to, but it cannot be directly traced to its origination input. Similar proposals include Coinshuffle in 2014 and Tumblebit in 2016, building on CoinJoin but not terribly popular [15],[16]. They fixed the need for a trusted third party to ‘mix’ the transactions. There are CoinJoin implementations that are being actively worked on but are not the most popular privacy solutions of today. A notable coin that uses CoinJoin technology is Dash, launched in January 2014, with masternodes in place of a trusted party.
COINJOIN

PROS

– Provides sender and receiver privacy
– Easy to implement on any cryptocurrency
– Lightweight
– Greater scalability with bulletproofs
– Mature technology

CONS

– Least anonymous privacy solution. Transaction amounts can be calculated
– Even without third-party mixer, depends on wealth centralization of masternodes

ZEROCOIN

Used in: Zcoin, PIVX
In May 2013, the Zerocoin protocol was introduced by John Hopkins University professor Matthew D. Green and his graduate students Ian Miers and Christina Garman.[17] In response to the need for use of a third party to do CoinJoin, the Zerocoin proposal allowed for a coin to be destroyed and remade in order to erase its history whenever it is spent. Zero-knowledge cryptography and zero-knowledge proofs are used to prove that the new coins for spending are being appropriately made. A zero-knowledge proof allows one party to prove to another that they know specific information, without revealing any information about it, other than the fact that they know it. Zerocoin was not accepted by the Bitcoin community as an implementation to be added to Bitcoin, so a new cryptocurrency had to be formed. Zcoin was the first cryptocurrency to implement the Zerocoin protocol in 2016. [18]
ZEROCOIN

PROS

– Provides sender and receiver privacy
– Supply can be audited
– Relatively mature technology
– Does not require a third-party

CONS

– Requires trusted setup (May not be required with Sigma protocol)
– Large proof sizes (not lightweight)
– Does not provide full privacy for transaction amounts

ZEROCASH

Used in: Zcash, Horizen, Komodo, Zclassic, Bitcoin Private
In May 2014, the current successor to the Zerocoin protocol, Zerocash, was created, also by Matthew Green and others (Eli Ben-Sasson, Alessandro Chiesa, Christina Garman, Matthew Green, Ian Miers, Eran Tromer, Madars Virza).[19] It improved upon the Zerocoin concept by taking advantage of zero-knowledge proofs called zk-snarks (zero knowledge succinct non-interactive arguments of knowledge). Unlike Zerocoin, which hid coin origins and payment history, Zerocash was faster, with smaller transaction sizes, and hides transaction information on the sender, receiver and amount. Zcash is the first cryptocurrency to implement the Zerocash protocol in 2016. [20]
ZEROCASH

PROS

– Provides full anonymity. Sender, receiver and amount hidden.
– Privacy can be default?
– Fast due to small proof sizes.
– Payment amount can be optionally disclosed for auditing
– Does not require any third-party

CONS

– Requires trusted setup. (May be improved with zt-starks technology)
– Supply cannot be audited. And coins can potentially be forged without proper implementation.
– Private transactions computationally intensive (improved with Sapling upgrade)

CONFIDENTIAL TRANSACTIONS

Used in: Monero and Particl with Ring Signatures as RING-CT
The next proposal from Maxwell was that of confidential transactions, proposed in June 2015 as part of the Sidechain Elements project from Blockstream, where Maxwell was Chief Technical Officer.[21],[22] It proposed to hide the transaction amount and asset type (e.g. deposits, currencies, shares), so that only the sender and receiver are aware of the amount, unless they choose to make the amount public. It uses homomorphic encryption[23] to encrypt the inputs and outputs by using blinding factors and a kind of ring signature in a commitment scheme, so the amount can be ‘committed’ to, without the amount actually being known. I’m terribly sorry if you now have the urge to go and research exactly what that means. The takeaway is that the transaction amount can be hidden from outsiders while being verifiable.
CONFIDENTIAL TRANSACTIONS

PROS

– Hides transaction amounts
– Privacy can be default
– Mature technology
– Does not require any third-party

CONS

– Only provides transaction amount privacy when used alone

RING-CT

Used in: Monero, Particl
Then came Ring Confidential transactions, proposed by Shen-Noether of Monero Research Labs in October 2015.[24] RingCT combines the use of ring signatures for hiding sender information, with the use of confidential transactions (which also uses ring signatures) for hiding amounts. The proposal described a new type of ring signature, A Multi-layered Linkable Spontaneous Anonymous Group signature which “allows for hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation”.[25] RingCT was implemented in Monero in January 2017 and made mandatory after September 2017.
RING -CONFIDENTIAL TRANSACTIONS

PROS

– Provides full anonymity. Hides transaction amounts and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume

MIMBLEWIMBLE

Used in: Grin
Mimblewimble was proposed in July 2016 by pseudonymous contributor Tom Elvis Jedusorand further developed in October 2016 by Andrew Poelstra.[26],[27] Mimblewimble is a “privacy and fungibility focused cryptocoin transaction structure proposal”.[28] The key words are transaction structure proposal, so the way the blockchain is built is different, in order to accommodate privacy and fungibility features. Mimblewimble uses the concept of Confidential transactions to keep amounts hidden, looks at private keys and transaction information to prove ownership of funds rather than using addresses, and bundles transactions together instead of listing them separately on the blockchain. It also introduces a novel method of pruning the blockchain. Grin is a cryptocurrency in development that is applying Mimblewimble. Mimblewimble is early in development and you can understand it more here [29].
MIMBLEWIMBLE

PROS

– Hides transaction amounts and receiver privacy
– Privacy is on by default
– Lightweight
– No public addresses?

CONS

– Privacy not very effective without high volume
– Sender and receiver must both be online
– Relatively new technology

ZEXE

Fresh off the minds of brilliant cryptographers (Sean Bowe, Alessandro Chiesa, Matthew Green, Ian Miers, Pratyush Mishra, Howard Wu), in October 2018 Zexe proposed a new cryptographic primitive called ‘decentralized private computation.[30] It allows users of a decentralized ledger to “execute offline computations that result in transactions”[31], but also keeps transaction amounts hidden and allows transaction validation to happen at any time regardless of computations being done online. This can have far reaching implications for privacy coins in the future. Consider cases where transactions need to be automatic and private, without both parties being present.

NETWORK PRIVACY

Privacy technologies that look at network privacy as nodes communicate with each other on the network are important considerations, rather than just looking at privacy on the blockchain itself. Anonymous layers encrypt and/or reroute data as it moves among peers, so it is not obvious who they originate from on the network. They are used to protect against surveillance or censorship from ISPs and governments. The Invisible Internet Project (I2P) is an anonymous network layer that uses end to end encryption for peers on a network to communicate with each other.[32] Its history dates back to 2003. Kovri is a Monero created implementation of I2P.[33] The Onion Router (Tor) is another anonymity layer [34]) that Verge is a privacy cryptocurrency that uses. But its historical link to the US government may be is concerning to some[35]. Dandelion transaction relay is also an upcoming Bitcoin improvement proposal (BIP) that scrambles IP data that will provide network privacy for Bitcoin as transaction and other information is transmitted.[36],[37],[38]

UPCOMING

Monero completed bulletproofs protocol updates that reduce RINGCT transaction sizes and thus transaction fee costs. (Bulletproofs are a replacement for range proofs used in confidential transactions that aid in encrypting inputs and outputs by making sure they add to zero).
Sigma Protocol – being actively researched by Zcoin team as of 2018 to replace Zerocoin protocol so that a trusted setup is not required.[39] There is a possible replacement for zk-snarks, called zk-starks, another form of zero-knowledge proof technology, that may make a trusted set-up unnecessary for zero-knowledege proof coins.[40]

PART 1 CONCLUSION OF THE PRIVACY COIN GUIDE ON THE TECHNOLOGY BEHIND PRIVACY COINS

Although Bitcoin is still a groundbreaking technology that gives us a trust-less transaction system, it has failed to live up to its expectations of privacy. Over time, new privacy technologies have arrived and are arriving with innovative and exciting solutions for Bitcoin’s lack of fungibility. It is important to note that these technologies are built on prior research and application, but we are considering their use in cryptocurrencies. Protocols are proposed based on cryptographic concepts that show how they would work, and then developers actually implement them. Please note that I did not include the possibility of improper implementation as a disadvantage, and the advantages assume that the technical development is well done. A very important point is that coins can also adapt new privacy technologies as their merits become obvious, even as they start with a specific privacy protocol. Furthermore, I am, unfortunately, positive that this is not an exhaustive overview and I am only covering publicized solutions. Next, we’ll talk more about the pros and cons and give an idea of how the coins can be compared.

There's a video version that can be watched, and you can find out how to get the second two parts if you want on my website (video link on the page): https://cryptoramble.com/guide-on-privacy-coins/
submitted by CryptoRamble to CryptoCurrencies [link] [comments]

The Privacy Coin Guide Part 1

As interest picks up in crypto again, I want to share this post I made on privacy coins again to just give the basics of their evolution. This is only part 1, and parts 2 and 3 are not available in this format, but this part is informative and basic.
If you’re looking for a quick and easy way to assess what the best privacy coin in the current space is, which has the best features, or which is most likely to give high returns, then this is not that guide. My goal is to give you the power to make your own decisions, to clearly state my biases, and educate. I really wanted to understand this niche of the crypto-space due to my background and current loyalties[1], and grasp the nuances of the features, origins and timelines of technologies used in privacy coins, while not being anything close to a developer myself. This is going to be a 3-part series, starting with an overview and basic review of the technology, then looking at its implications, and ending with why I like a specific project. It might be mildly interesting or delightfully educational. Cryptocurrencies are young and existing privacy coins are deploying technology that is a work in progress. This series assumes a basic understanding of how blockchains work, specifically as used in cryptocurrencies. If you don’t have that understanding, might I suggest that you get it? [2],[3],[4] Because cryptocurrencies have a long way to go before reaching their end-game: when the world relies on the technology without understanding it. So, shall we do a deep dive into the privacy coin space?

FIRST THERE WAS BITCOIN

Cryptocurrencies allow you to tokenize value and track its exchange between hands over time, with transaction information verified by a distributed network of users. The most famous version of a cryptocurrency in use is Bitcoin, defined as peer-to-peer electronic cash. [5] Posted anonymously in 2008, the whitepaper seemed to be in direct response to the global financial meltdown and public distrust of the conventional banking and financing systems. Although cryptographic techniques are used in Bitcoin to ensure that (i) only the owner of a specific wallet has the authority to spend funds from that wallet, (ii) the public address is linked but cannot be traced by a third party to the private address (iii) the information is stored via cryptographic hashing in a merkle tree structure to ensure data integrity, the actual transaction information is publicly visible on the blockchain and can be traced back to the individual through chain analysis.[6] This has raised fears of possible financial censorship or the metaphorical tainting of money due to its origination point, as demonstrated in the Silk Road marketplace disaster.[7] This can happen because fiat money is usually exchanged for cryptocurrency at some point, as crypto-enthusiasts are born in the real world and inevitably cash out. There are already chain analysis firms and software that are increasingly efficient at tracking transactions on the Bitcoin blockchain.[8] This lack of privacy is one of the limitations of Bitcoin that has resulted in the creation of altcoins that experiment with the different features a cryptocurrency can have. Privacy coins are figuring out how to introduce privacy in addition to the payment network. The goal is to make the cryptocurrency fungible, each unit able to be exchanged for equal value without knowledge of its transaction history – like cash, while being publicly verifiable on a decentralized network. In other words, anyone can add the math up without being able to see the full details. Some privacy solutions and protocols have popped up as a result:

CRYPTONOTE – RING SIGNATURES AND STEALTH ADDRESSES

Used in: Monero and Particl as its successor RING-CT, Bytecoin
In December 2012, CryptoNote introduced the use of ring signatures and stealth addresses (along with other notable features such as its own codebase) to improve cryptocurrency privacy.[9] An updated CryptoNote version 2 came in October 2013 [10](though there is some dispute over this timeline [11]), also authored under the name Nicolas van Saberhagen. Ring signatures hide sender information by having the sender sign a transaction using a signature that could belong to multiple users. This makes a transaction untraceable. Stealth addresses allow a receiver to give a single address which generates a different public address for funds to be received at each time funds are sent to it. That makes a transaction unlinkable. In terms of privacy, CryptoNote gave us a protocol for untraceable and unlinkable transactions. The first implementation of CryptoNote technology was Bytecoin in March 2014 (timeline disputed [12]), which spawned many children (forks) in subsequent years, a notable example being Monero, based on CryptoNote v2 in April 2014.
RING SIGNATURES and STEALTH ADDRESSES

PROS

– Provides sender and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume
-Does not hide transaction information if not combined with another protocol.

COINJOIN

Used in: Dash
Bitcoin developer Gregory Maxwell proposed a set of solutions to bring privacy to Bitcoin and cryptocurrencies, the first being CoinJoin (January 28 – Aug 22, 2013).[13],[14] CoinJoin (sometimes called CoinSwap) allows multiple users to combine their transactions into a single transaction, by receiving inputs from multiple users, and then sending their outputs to the multiple users, irrespective of who in the group the inputs came from. So, the receiver will get whatever output amount they were supposed to, but it cannot be directly traced to its origination input. Similar proposals include Coinshuffle in 2014 and Tumblebit in 2016, building on CoinJoin but not terribly popular [15],[16]. They fixed the need for a trusted third party to ‘mix’ the transactions. There are CoinJoin implementations that are being actively worked on but are not the most popular privacy solutions of today. A notable coin that uses CoinJoin technology is Dash, launched in January 2014, with masternodes in place of a trusted party.
COINJOIN

PROS

– Provides sender and receiver privacy
– Easy to implement on any cryptocurrency
– Lightweight
– Greater scalability with bulletproofs
– Mature technology

CONS

– Least anonymous privacy solution. Transaction amounts can be calculated
– Even without third-party mixer, depends on wealth centralization of masternodes

ZEROCOIN

Used in: Zcoin, PIVX
In May 2013, the Zerocoin protocol was introduced by John Hopkins University professor Matthew D. Green and his graduate students Ian Miers and Christina Garman.[17] In response to the need for use of a third party to do CoinJoin, the Zerocoin proposal allowed for a coin to be destroyed and remade in order to erase its history whenever it is spent. Zero-knowledge cryptography and zero-knowledge proofs are used to prove that the new coins for spending are being appropriately made. A zero-knowledge proof allows one party to prove to another that they know specific information, without revealing any information about it, other than the fact that they know it. Zerocoin was not accepted by the Bitcoin community as an implementation to be added to Bitcoin, so a new cryptocurrency had to be formed. Zcoin was the first cryptocurrency to implement the Zerocoin protocol in 2016. [18]
ZEROCOIN

PROS

– Provides sender and receiver privacy
– Supply can be audited
– Relatively mature technology
– Does not require a third-party

CONS

– Requires trusted setup (May not be required with Sigma protocol)
– Large proof sizes (not lightweight)
– Does not provide full privacy for transaction amounts

ZEROCASH

Used in: Zcash, Horizen, Komodo, Zclassic, Bitcoin Private
In May 2014, the current successor to the Zerocoin protocol, Zerocash, was created, also by Matthew Green and others (Eli Ben-Sasson, Alessandro Chiesa, Christina Garman, Matthew Green, Ian Miers, Eran Tromer, Madars Virza).[19] It improved upon the Zerocoin concept by taking advantage of zero-knowledge proofs called zk-snarks (zero knowledge succinct non-interactive arguments of knowledge). Unlike Zerocoin, which hid coin origins and payment history, Zerocash was faster, with smaller transaction sizes, and hides transaction information on the sender, receiver and amount. Zcash is the first cryptocurrency to implement the Zerocash protocol in 2016. [20]
ZEROCASH

PROS

– Provides full anonymity. Sender, receiver and amount hidden.
– Privacy can be default?
– Fast due to small proof sizes.
– Payment amount can be optionally disclosed for auditing
– Does not require any third-party

CONS

– Requires trusted setup. (May be improved with zt-starks technology)
– Supply cannot be audited. And coins can potentially be forged without proper implementation.
– Private transactions computationally intensive (improved with Sapling upgrade)

CONFIDENTIAL TRANSACTIONS

Used in: Monero and Particl with Ring Signatures as RING-CT
The next proposal from Maxwell was that of confidential transactions, proposed in June 2015 as part of the Sidechain Elements project from Blockstream, where Maxwell was Chief Technical Officer.[21],[22] It proposed to hide the transaction amount and asset type (e.g. deposits, currencies, shares), so that only the sender and receiver are aware of the amount, unless they choose to make the amount public. It uses homomorphic encryption[23] to encrypt the inputs and outputs by using blinding factors and a kind of ring signature in a commitment scheme, so the amount can be ‘committed’ to, without the amount actually being known. I’m terribly sorry if you now have the urge to go and research exactly what that means. The takeaway is that the transaction amount can be hidden from outsiders while being verifiable.
CONFIDENTIAL TRANSACTIONS

PROS

– Hides transaction amounts
– Privacy can be default
– Mature technology
– Does not require any third-party

CONS

– Only provides transaction amount privacy when used alone

RING-CT

Used in: Monero, Particl
Then came Ring Confidential transactions, proposed by Shen-Noether of Monero Research Labs in October 2015.[24] RingCT combines the use of ring signatures for hiding sender information, with the use of confidential transactions (which also uses ring signatures) for hiding amounts. The proposal described a new type of ring signature, A Multi-layered Linkable Spontaneous Anonymous Group signature which “allows for hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation”.[25] RingCT was implemented in Monero in January 2017 and made mandatory after September 2017.
RING -CONFIDENTIAL TRANSACTIONS

PROS

– Provides full anonymity. Hides transaction amounts and receiver privacy
– Privacy can be default
– Mature technology
– Greater scalability with bulletproofs
– Does not require any third-party

CONS

– Privacy not very effective without high volume

MIMBLEWIMBLE

Used in: Grin
Mimblewimble was proposed in July 2016 by pseudonymous contributor Tom Elvis Jedusorand further developed in October 2016 by Andrew Poelstra.[26],[27] Mimblewimble is a “privacy and fungibility focused cryptocoin transaction structure proposal”.[28] The key words are transaction structure proposal, so the way the blockchain is built is different, in order to accommodate privacy and fungibility features. Mimblewimble uses the concept of Confidential transactions to keep amounts hidden, looks at private keys and transaction information to prove ownership of funds rather than using addresses, and bundles transactions together instead of listing them separately on the blockchain. It also introduces a novel method of pruning the blockchain. Grin is a cryptocurrency in development that is applying Mimblewimble. Mimblewimble is early in development and you can understand it more here [29].
MIMBLEWIMBLE

PROS

– Hides transaction amounts and receiver privacy
– Privacy is on by default
– Lightweight
– No public addresses?

CONS

– Privacy not very effective without high volume
– Sender and receiver must both be online
– Relatively new technology

ZEXE

Fresh off the minds of brilliant cryptographers (Sean Bowe, Alessandro Chiesa, Matthew Green, Ian Miers, Pratyush Mishra, Howard Wu), in October 2018 Zexe proposed a new cryptographic primitive called ‘decentralized private computation.[30] It allows users of a decentralized ledger to “execute offline computations that result in transactions”[31], but also keeps transaction amounts hidden and allows transaction validation to happen at any time regardless of computations being done online. This can have far reaching implications for privacy coins in the future. Consider cases where transactions need to be automatic and private, without both parties being present.

NETWORK PRIVACY

Privacy technologies that look at network privacy as nodes communicate with each other on the network are important considerations, rather than just looking at privacy on the blockchain itself. Anonymous layers encrypt and/or reroute data as it moves among peers, so it is not obvious who they originate from on the network. They are used to protect against surveillance or censorship from ISPs and governments. The Invisible Internet Project (I2P) is an anonymous network layer that uses end to end encryption for peers on a network to communicate with each other.[32] Its history dates back to 2003. Kovri is a Monero created implementation of I2P.[33] The Onion Router (Tor) is another anonymity layer [34]) that Verge is a privacy cryptocurrency that uses. But its historical link to the US government may be is concerning to some[35]. Dandelion transaction relay is also an upcoming Bitcoin improvement proposal (BIP) that scrambles IP data that will provide network privacy for Bitcoin as transaction and other information is transmitted.[36],[37],[38]

UPCOMING

Monero completed bulletproofs protocol updates that reduce RINGCT transaction sizes and thus transaction fee costs. (Bulletproofs are a replacement for range proofs used in confidential transactions that aid in encrypting inputs and outputs by making sure they add to zero).
Sigma Protocol – being actively researched by Zcoin team as of 2018 to replace Zerocoin protocol so that a trusted setup is not required.[39] There is a possible replacement for zk-snarks, called zk-starks, another form of zero-knowledge proof technology, that may make a trusted set-up unnecessary for zero-knowledege proof coins.[40]

PART 1 CONCLUSION OF THE PRIVACY COIN GUIDE ON THE TECHNOLOGY BEHIND PRIVACY COINS

Although Bitcoin is still a groundbreaking technology that gives us a trust-less transaction system, it has failed to live up to its expectations of privacy. Over time, new privacy technologies have arrived and are arriving with innovative and exciting solutions for Bitcoin’s lack of fungibility. It is important to note that these technologies are built on prior research and application, but we are considering their use in cryptocurrencies. Protocols are proposed based on cryptographic concepts that show how they would work, and then developers actually implement them. Please note that I did not include the possibility of improper implementation as a disadvantage, and the advantages assume that the technical development is well done. A very important point is that coins can also adapt new privacy technologies as their merits become obvious, even as they start with a specific privacy protocol. Furthermore, I am, unfortunately, positive that this is not an exhaustive overview and I am only covering publicized solutions. Next, we’ll talk more about the pros and cons and give an idea of how the coins can be compared.

There's a video version that can be watched, and you can find out how to get the second two parts if you want on my website (video link on the page): https://cryptoramble.com/guide-on-privacy-coins/
submitted by CryptoRamble to ethtrader [link] [comments]

What is Zero Knowledge Proof? MIT Bitcoin Expo 2019 - Zero Knowledge Proofs and Smart Contracts with Bulletproofs Zero Knowledge Proofs - ZK-SNARKS ZenCash ZCash The Anonymity of Bitcoin – Zero-Knowledge Proof and Ring Signature Technologies – Blockchain 101 Ep 58 - What is Zero knowledge Proof?

The concept of interactive zero-knowledge proof systems was first introduced by Shafi Goldwasser and Silvio Micali in the late 1980’s, and the general assumption of how the proof of a given statement as such contains more knowledge than the sole true/false validity of that statement (making use of auxilary inputs, “trapdoors”, etc.) underpins much of modern cryptography since. Zcash, a hard-fork of Bitcoin, became the pioneer in zero-knowledge proof application in late 2016 with the use of a specific implementation of zero-knowledge proofs called zk-SNARKs, with “zk ... Zero-knowledge proof or zero-knowledge protocol is a method by which one party (the prover) can prove to another party (the verifier) that a given statement is true, without conveying any information apart from the fact that the statement is indeed true. The concept of zero-knowledge proofs was first conceived in 1989 by Shafi Goldwasser, Silvio Micali and Charles Rackoff in their paper "The Knowledge Complexity of Interactive Proof-Systems". This paper introduced the concept of interactive proof systems which deals with Knowledge complexity, a measurement of amount of knowledge about the proof transferred from the prover to the verifier. A zero-knowledge proof lets someone prove a mathematical fact to another person without teaching them anything about the fact itself. It has been proven that you can convert any computer program into a zero-knowledge proof (this is referred to mathematically as PSPACE⊂IP). So, using a zero-knowledge proof I could prove to you that I know some ...

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What is Zero Knowledge Proof?

Zero-knowledge Proof refers to the system which one can prove to the verifier a given statement is true without revealing additional information. At present, the highly anonymous cryptocurrency ... MIT Bitcoin Expo 2019 - Zero Knowledge Proofs and Smart Contracts with Bulletproofs - Duration: 27:11. MIT Bitcoin Club 1,862 views. 27:11. Silvio Micali: Proofs, Knowledge, and Computation ... Cathie Yun (Cryptographer, Interstellar) presenting on zero knowledge proofs and smart contracts at the 2019 MIT Bitcoin Expo. MIT Bitcoin Expo 2019 - Zero Knowledge Proofs and Smart Contracts with Bulletproofs - Duration: 27:11. MIT Bitcoin Club 2,480 views. 27:11. Dystopia Labs (Part 1/3) Demystifying Zero Knowledge ... Blockchain, zero knowledge proofs, and data privacy. This video is part of a non-technical series on blockchain I'm doing: https://www.youtube.com/watch?v=lr...

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