15 ms·

The Zcash Anonymous Cryptocurrency [video]

70 points by ianopolous 10y ago

droffel 10y ago
The title of this talk is 'zero knowledge succinct non-interactive arguments of knowledge for laypeople', yet the speaker (at 1:40 in the talk), says he won't be able to explain how they work. ZCash, at least for the first 3 builds, did not have their primary feature (fully anonymous transactions) working. I don't believe thats fixed yet (is it?). How they missed their primary feature being broken before releasing, I have no idea.
- woah 10y ago
  Wasn't the issue just that they couldn't mine into anonymous addresses?
  - droffel 10y ago
    The issue prevented all transactions which had all z-address inputs and outputs (that is, fully anon txes) and no t-address inputs or outputs (public addresses) from being mined.
    - biafra 10y ago
      What is your source for this claim? I did these kind of transactions during the beta.
      - plasticmachine 10y ago
        This is well known: https://github.com/zcash/zcash/issues/1705 https://github.com/zcash/zcash/issues/1705
        biafra 10y ago
        The ticket says "In some cases, some transactions with joinsplits do not get mined." So this does not prove droffels point. He said all tx with only z-addresses could not be mined. Any other source for this claim?
        plasticmachine 10y ago
        He's 100% correct, as is the GitHub issue. Transactions that were z-addr -> t-addr, or vice versa, were being mined, but private transactions (my z-addr pays your z-addr) were not. Per the ZCash website (https://z.cash/blog/state-of-the-network-2016-10-31.html https://z.cash/blog/state-of-the-network-2016-10-31.html) - "There is one known bug, which causes private transactions (those in which all of the inputs and outputs are shielded addresses) to not get mined."
    - biafra 10y ago
      I am sure, you're mistaken. I just created and executed a tx with only z-addresses with zcashd version 1.0.1. It was mined and can be found on the block exlorer. Please stop spreading FUD about zcash.
      - plasticmachine 10y ago
        It's not FUD, he's entirely correct. They had one thing to get right before launch, and they got it wrong. Speaks volumes for the so-called dream team. References: - https://github.com/zcash/zcash/issues/1705 https://github.com/zcash/zcash/issues/1705 - https://www.cryptocoinsnews.com/zcash-bug-prevents-private-transactions-soon-after-launch/ https://www.cryptocoinsnews.com/zcash-bug-prevents-private-t...
        biafra 10y ago
        It is FUD, because droffel claims no private tx could be mined.
        plasticmachine 10y ago
        No he doesn't. Go read what he wrote again. Private transactions (one z-addr sends to another z-addr) were not being mined.
- ianpurton 10y ago
  It is fixed and was fixed a long time ago.
  - plasticmachine 10y ago
    "A long time ago" being less than 2 months ago. https://github.com/zcash/zcash/commit/9eb852edd0c9a20d7e39251d24f3b84d9376d50f https://github.com/zcash/zcash/commit/9eb852edd0c9a20d7e3925...
nickik 10y ago
Not the best talk by far. Its just a real simple intro. All the developers of Zcash were in the audience and then there is some associated guy giving a intro. I thought it was a bit pointless.
kneel 10y ago
Can't take zcash seriously. The entire currency is programmed to give 10% of all zcash to the developers.
- meowface 10y ago
  I think that's a fair share given the amount of work that's gone into it.
  - kneel 10y ago
    First time I've heard of this practice, it's a very very large percent of the pie. Makes me wonder why they don't just mine?
    - nickik 10y ago
      The alternative is premining. The went for this model because it it more transparent.
      - plasticmachine 10y ago
        Really? So Bitcoin and Monero only work because of their premine...?
  - biafra 10y ago
    Although I think it is obvious. I mention it anyway. The founders fee that goes to the developers is meant to fund the development for the next four years. If you don't like that, there is already the Zclassic fork wihout the founders fee.
  - plasticmachine 10y ago
    You know that it's forked from Bitcoin right? What portion of the tax is being given to the Bitcoin developers?
- robert_foss 10y ago
  Isn't it 20?
EvilMonkeyMat 10y ago
I've said it before: Zcash has nothing Monero isn't already offering. And like others said, right now, I still haven't seen a mining pool or an exchange that can handle anonymous transactions. An example: http://zcash.flypool.org/ http://zcash.flypool.org/ Also, Zcash had an initial trusted setup ceremony after which the 6 participants supposedly all deleted their private keys. You DO have to trust none of those have colluded to someday, for example, start creating zcash coins for their own good without anyone knowing. All the info here: https://petertodd.org/2016/cypherpunk-desert-bus-zcash-trusted-setup-ceremony https://petertodd.org/2016/cypherpunk-desert-bus-zcash-trust...
- FiloSottile 10y ago
  And as others said before, Monero does some sketchy weak mixing of something like a 100 tx, which is really not enough for long term anonymity (think what happens when the other 99 outputs are spent). EDIT: there are a couple papers linked in a child comment that seem to analyze this which I haven't read entirely yet; the following two points still stand. You don't need an exchange to use z-addresses, just receive into a one-use t, and then make it disappear into your main z-address yourself. Finally, you have to trust that AT LEAST ONE won't collude, because you need all pieces to fake Zcash, which is very different. Enough with this FUD. It's innovative tech, I expected HN to appreciate it more than the usual cryptocurrency circles.
  - deleted 10y ago
    [deleted]
  - deleted 10y ago
    [deleted]
  - otheotheothe 10y ago
    Hello Mr. Cloudflare, Your whole understanding of how XMR works seems to be wrong; theres no concept of spend outputs at all, to deanonymize tx with a certain certainity one would have to own around 83% of the networks outputs. Theres a good academic read about this here: https://lab.getmonero.org/pubs/MRL-0001.pdf https://lab.getmonero.org/pubs/MRL-0001.pdf and here: https://lab.getmonero.org/pubs/MRL-0004.pdf https://lab.getmonero.org/pubs/MRL-0004.pdf And also a privacy improvement which gets into effect in about 25 hours or so with the next hardfork called RingCT, which has been peer reviewed by Ledger journal: http://www.ledgerjournal.org/ojs/index.php/ledger/article/download/34/45 http://www.ledgerjournal.org/ojs/index.php/ledger/article/do... Optional privacy a la ZCASH is broken by design and cannot work, you are still able to have tainted coins and do blacklisting etc, its effectily useless, also it opens up a whole world of other attack vectors like this one: https://github.com/zcash/zcash/issues/1360#issuecomment-246109488 https://github.com/zcash/zcash/issues/1360#issuecomment-2461... A good read for everyone unbiased tho a bit old is here (which explains the inner workings): https://lab.getmonero.org/pubs/MRL-0003.pdf https://lab.getmonero.org/pubs/MRL-0003.pdf
wildchild 10y ago
ZCash is scam.
- anon13 10y ago
  Zcash is the most technologically advanced cryptocurrency existing today to effectively accomplish mathematically proven private transactions. Built with love for all Planet Earth privacy loving users. Use it, test it and you will love it too!
  - plasticmachine 10y ago
    Ummmm no. 1. It's controlled by a corporation with VC backing. This leads to a single point of failure, a ton of disincentives, and makes it easier for an attacker. 2. The cryptography is untested, unproven, and too new to be trusted. Since when did technically competent people advocate for cryptography like that?? 3. The 20% tax puts a crazy amount of strain on the economic system, and is inordinately high. 4. The trusted setup is hard to get right, but they completely screwed it up (see my comment upthread). 5. Private transactions take 8gb+ of RAM and several minutes to compute on my laptop, how is that at all scalable or useful? We should be immensely critical of new cryptography being rushed into production at the behest of investors, and we should not be promoting a centralized, corporate-controlled cryptocurrency.
    - anon13 10y ago
      Answers to your concerns below: 1. As a Bitcoin fork and descendant it is not controlled by anyone but by its network of users. Therefore there is no single point of failure. Development is done today by a corporation with VC backing which does not necessarily mean that will continue to be the case tomorrow. A community of developers and/or users can take the development leadership at any point in the future if it were so needed. 2. The cryptography is currently superior to any other. It has been tested and proven. It is in your hands to prove it wrong. Please do so. 3. The founders reward provides even more security and development resources during the first 4 years. Many people see it in fact as an advantage. 4. The trusted setup process whitepaper has been made public, plus the participants are also known. You can research and certify the process and contact the participants as you wish since it is all public. Please provide the exact point of failure in the process and where exactly has it failed. It seems like a highly secure setup to me. 5. The RAM and time required for private transactions can be done with no problem at all by most users with laptops as of today. Even so, there is development going on by the Zcash team to improve the performance and reduce the ram and time required. In the spirit of Bitcoin, Zcash is decentralized and built for privacy loving users.
chx 10y ago
Can anyone explain to me why do we call these things currencies? There's to start with https://www.washingtonpost.com/news/wonk/wp/2015/06/08/bitcoin-isnt-the-future-of-money-its-either-a-ponzi-scheme-or-a-pyramid-scheme/ https://www.washingtonpost.com/news/wonk/wp/2015/06/08/bitco... and then https://www.wired.com/2017/01/bitcoin-will-never-currency-something-way-weirder/ https://www.wired.com/2017/01/bitcoin-will-never-currency-so...
- knocte 10y ago
  https://99bitcoins.com/bitcoinobituaries/ https://99bitcoins.com/bitcoinobituaries/
  - chx 10y ago
    I haven't said anything about Bitcoin dying, I am just saying it's not a currency.
woah 10y ago
This thread doesn't seem to have any discussion of the linked video, it's full of people trying to push something called Monero
- plasticmachine 10y ago
  It's being presented as an alternative that doesn't cut corners or make the incredibly dangerous compromises ZCash does. Would you expect a thread lauding SnapChat as a privacy enhancing messaging app to not have a bunch of people, finding the suggestion ludicrous, "pushing" Signal? As to the video, the talk was pathetic. The speaker claimed he was going to explain zk-SNARKS to the layperson, then immediately claimed to not understand them. It presented none of the risks of ZCash, and only really covered how joinsplits work.
- aminorex 10y ago
  ...because we like monero, consider the technology more appropriate and mature for the task, and wish to use it. Currency abhors liquidity barriers, slippage, etc. Since Monero is the most liquid crypto that provides acceptable privacy and hence fungibility, it is a win-win situation if it is universally adopted. Also the corrupt terms of the zcash social contract make it abhorrent to many of us, who believe in open source, peer-review, and decentralization of authority, as well as casting deep suspicion on the motivations of the beneficiaries of zcash's corporate structure, and the acts which self-interest will therefore dictate.
anon13 10y ago
It seems like the Monero guys can not stand that Zcash is the de facto standard for private transactions and the clear technological leader. Long live Zcash! for the benefit of all privacy loving users. On the other hand spreading FUD and lies does not speak well of Monero. That in addition to the mathematically weaker and inferior tech used by Monero.
- plasticmachine 10y ago
  Or maybe we're just not buying into cryptography being pushed by a company that has a marketing department.
  - anon13 10y ago
    For sure any marketing that they (Zcash) have is no so active as the Monero guys are spreading lies and confusion around. May be we should all abandon the privacy ship, join the Monero guys (no matter its obscure origins by the way) and spread FUD and lies about any better tech like Zcash or others that comes up, right?
    - plasticmachine 10y ago
      By "the Monero guys" you mean the broader technical community that understand security software design? Also, obscure origins are irrelevant when the technology is solid. Take the following examples: TrueCrypt, Bitcoin, MimbleWimble. Are you honestly arguing that TrueCrypt was bad?
      - anon13 10y ago
        By the "Monero guys spreading FUD and lies" I mean exactly that. I have used Monero in the past and consider myself part of that comunity at the time. Even used its predecessor Bytecoin for a while before Monero came up. I have researched a lot and just happen to like and trust Zcash tech much more! May be you should do a bit more research. It is nice to have competing privacy technologies. It is good for privacy loving users and for the advancement of the field. If you like Monero and feel is much better, good for you, use it and enjoy it, this is a free world, but there is no need to lie and confuse people about Zcash.

70 points by ianopolous 10y ago

The title of this talk is 'zero knowledge succinct non-interactive arguments of knowledge for laypeople', yet the speaker (at 1:40 in the talk), says he won't be able to explain how they work. ZCash, at least for the first 3 builds, did not have their primary feature (fully anonymous transactions) working. I don't believe thats fixed yet (is it?). How they missed their primary feature being broken before releasing, I have no idea.

woah 10y ago
Wasn't the issue just that they couldn't mine into anonymous addresses?
- droffel 10y ago
  The issue prevented all transactions which had all z-address inputs and outputs (that is, fully anon txes) and no t-address inputs or outputs (public addresses) from being mined.
  - biafra 10y ago
    What is your source for this claim? I did these kind of transactions during the beta.
    - plasticmachine 10y ago
      This is well known: https://github.com/zcash/zcash/issues/1705 https://github.com/zcash/zcash/issues/1705
      - biafra 10y ago
        The ticket says "In some cases, some transactions with joinsplits do not get mined." So this does not prove droffels point. He said all tx with only z-addresses could not be mined. Any other source for this claim?
        plasticmachine 10y ago
        He's 100% correct, as is the GitHub issue. Transactions that were z-addr -> t-addr, or vice versa, were being mined, but private transactions (my z-addr pays your z-addr) were not. Per the ZCash website (https://z.cash/blog/state-of-the-network-2016-10-31.html https://z.cash/blog/state-of-the-network-2016-10-31.html) - "There is one known bug, which causes private transactions (those in which all of the inputs and outputs are shielded addresses) to not get mined."
  - biafra 10y ago
    I am sure, you're mistaken. I just created and executed a tx with only z-addresses with zcashd version 1.0.1. It was mined and can be found on the block exlorer. Please stop spreading FUD about zcash.
    - plasticmachine 10y ago
      It's not FUD, he's entirely correct. They had one thing to get right before launch, and they got it wrong. Speaks volumes for the so-called dream team. References: - https://github.com/zcash/zcash/issues/1705 https://github.com/zcash/zcash/issues/1705 - https://www.cryptocoinsnews.com/zcash-bug-prevents-private-transactions-soon-after-launch/ https://www.cryptocoinsnews.com/zcash-bug-prevents-private-t...
      - biafra 10y ago
        It is FUD, because droffel claims no private tx could be mined.
        plasticmachine 10y ago
        No he doesn't. Go read what he wrote again. Private transactions (one z-addr sends to another z-addr) were not being mined.
ianpurton 10y ago
It is fixed and was fixed a long time ago.
- plasticmachine 10y ago
  "A long time ago" being less than 2 months ago. https://github.com/zcash/zcash/commit/9eb852edd0c9a20d7e39251d24f3b84d9376d50f https://github.com/zcash/zcash/commit/9eb852edd0c9a20d7e3925...

nickik 10y ago

Not the best talk by far. Its just a real simple intro. All the developers of Zcash were in the audience and then there is some associated guy giving a intro. I thought it was a bit pointless.

kneel 10y ago

Can't take zcash seriously. The entire currency is programmed to give 10% of all zcash to the developers.

meowface 10y ago
I think that's a fair share given the amount of work that's gone into it.
- kneel 10y ago
  First time I've heard of this practice, it's a very very large percent of the pie. Makes me wonder why they don't just mine?
  - nickik 10y ago
    The alternative is premining. The went for this model because it it more transparent.
    - plasticmachine 10y ago
      Really? So Bitcoin and Monero only work because of their premine...?
- biafra 10y ago
  Although I think it is obvious. I mention it anyway. The founders fee that goes to the developers is meant to fund the development for the next four years. If you don't like that, there is already the Zclassic fork wihout the founders fee.
- plasticmachine 10y ago
  You know that it's forked from Bitcoin right? What portion of the tax is being given to the Bitcoin developers?
robert_foss 10y ago
Isn't it 20?

EvilMonkeyMat 10y ago

I've said it before: Zcash has nothing Monero isn't already offering. And like others said, right now, I still haven't seen a mining pool or an exchange that can handle anonymous transactions. An example: http://zcash.flypool.org/ http://zcash.flypool.org/ Also, Zcash had an initial trusted setup ceremony after which the 6 participants supposedly all deleted their private keys. You DO have to trust none of those have colluded to someday, for example, start creating zcash coins for their own good without anyone knowing. All the info here: https://petertodd.org/2016/cypherpunk-desert-bus-zcash-trusted-setup-ceremony https://petertodd.org/2016/cypherpunk-desert-bus-zcash-trust...

FiloSottile 10y ago
And as others said before, Monero does some sketchy weak mixing of something like a 100 tx, which is really not enough for long term anonymity (think what happens when the other 99 outputs are spent). EDIT: there are a couple papers linked in a child comment that seem to analyze this which I haven't read entirely yet; the following two points still stand. You don't need an exchange to use z-addresses, just receive into a one-use t, and then make it disappear into your main z-address yourself. Finally, you have to trust that AT LEAST ONE won't collude, because you need all pieces to fake Zcash, which is very different. Enough with this FUD. It's innovative tech, I expected HN to appreciate it more than the usual cryptocurrency circles.
- deleted 10y ago
  [deleted]
- deleted 10y ago
  [deleted]
- otheotheothe 10y ago
  Hello Mr. Cloudflare, Your whole understanding of how XMR works seems to be wrong; theres no concept of spend outputs at all, to deanonymize tx with a certain certainity one would have to own around 83% of the networks outputs. Theres a good academic read about this here: https://lab.getmonero.org/pubs/MRL-0001.pdf https://lab.getmonero.org/pubs/MRL-0001.pdf and here: https://lab.getmonero.org/pubs/MRL-0004.pdf https://lab.getmonero.org/pubs/MRL-0004.pdf And also a privacy improvement which gets into effect in about 25 hours or so with the next hardfork called RingCT, which has been peer reviewed by Ledger journal: http://www.ledgerjournal.org/ojs/index.php/ledger/article/download/34/45 http://www.ledgerjournal.org/ojs/index.php/ledger/article/do... Optional privacy a la ZCASH is broken by design and cannot work, you are still able to have tainted coins and do blacklisting etc, its effectily useless, also it opens up a whole world of other attack vectors like this one: https://github.com/zcash/zcash/issues/1360#issuecomment-246109488 https://github.com/zcash/zcash/issues/1360#issuecomment-2461... A good read for everyone unbiased tho a bit old is here (which explains the inner workings): https://lab.getmonero.org/pubs/MRL-0003.pdf https://lab.getmonero.org/pubs/MRL-0003.pdf

wildchild 10y ago

ZCash is scam.

anon13 10y ago
Zcash is the most technologically advanced cryptocurrency existing today to effectively accomplish mathematically proven private transactions. Built with love for all Planet Earth privacy loving users. Use it, test it and you will love it too!
- plasticmachine 10y ago
  Ummmm no. 1. It's controlled by a corporation with VC backing. This leads to a single point of failure, a ton of disincentives, and makes it easier for an attacker. 2. The cryptography is untested, unproven, and too new to be trusted. Since when did technically competent people advocate for cryptography like that?? 3. The 20% tax puts a crazy amount of strain on the economic system, and is inordinately high. 4. The trusted setup is hard to get right, but they completely screwed it up (see my comment upthread). 5. Private transactions take 8gb+ of RAM and several minutes to compute on my laptop, how is that at all scalable or useful? We should be immensely critical of new cryptography being rushed into production at the behest of investors, and we should not be promoting a centralized, corporate-controlled cryptocurrency.
  - anon13 10y ago
    Answers to your concerns below: 1. As a Bitcoin fork and descendant it is not controlled by anyone but by its network of users. Therefore there is no single point of failure. Development is done today by a corporation with VC backing which does not necessarily mean that will continue to be the case tomorrow. A community of developers and/or users can take the development leadership at any point in the future if it were so needed. 2. The cryptography is currently superior to any other. It has been tested and proven. It is in your hands to prove it wrong. Please do so. 3. The founders reward provides even more security and development resources during the first 4 years. Many people see it in fact as an advantage. 4. The trusted setup process whitepaper has been made public, plus the participants are also known. You can research and certify the process and contact the participants as you wish since it is all public. Please provide the exact point of failure in the process and where exactly has it failed. It seems like a highly secure setup to me. 5. The RAM and time required for private transactions can be done with no problem at all by most users with laptops as of today. Even so, there is development going on by the Zcash team to improve the performance and reduce the ram and time required. In the spirit of Bitcoin, Zcash is decentralized and built for privacy loving users.

chx 10y ago

Can anyone explain to me why do we call these things currencies? There's to start with https://www.washingtonpost.com/news/wonk/wp/2015/06/08/bitcoin-isnt-the-future-of-money-its-either-a-ponzi-scheme-or-a-pyramid-scheme/ https://www.washingtonpost.com/news/wonk/wp/2015/06/08/bitco... and then https://www.wired.com/2017/01/bitcoin-will-never-currency-something-way-weirder/ https://www.wired.com/2017/01/bitcoin-will-never-currency-so...

knocte 10y ago
https://99bitcoins.com/bitcoinobituaries/ https://99bitcoins.com/bitcoinobituaries/
- chx 10y ago
  I haven't said anything about Bitcoin dying, I am just saying it's not a currency.

woah 10y ago

This thread doesn't seem to have any discussion of the linked video, it's full of people trying to push something called Monero

plasticmachine 10y ago
It's being presented as an alternative that doesn't cut corners or make the incredibly dangerous compromises ZCash does. Would you expect a thread lauding SnapChat as a privacy enhancing messaging app to not have a bunch of people, finding the suggestion ludicrous, "pushing" Signal? As to the video, the talk was pathetic. The speaker claimed he was going to explain zk-SNARKS to the layperson, then immediately claimed to not understand them. It presented none of the risks of ZCash, and only really covered how joinsplits work.
aminorex 10y ago
...because we like monero, consider the technology more appropriate and mature for the task, and wish to use it. Currency abhors liquidity barriers, slippage, etc. Since Monero is the most liquid crypto that provides acceptable privacy and hence fungibility, it is a win-win situation if it is universally adopted. Also the corrupt terms of the zcash social contract make it abhorrent to many of us, who believe in open source, peer-review, and decentralization of authority, as well as casting deep suspicion on the motivations of the beneficiaries of zcash's corporate structure, and the acts which self-interest will therefore dictate.

anon13 10y ago

It seems like the Monero guys can not stand that Zcash is the de facto standard for private transactions and the clear technological leader. Long live Zcash! for the benefit of all privacy loving users. On the other hand spreading FUD and lies does not speak well of Monero. That in addition to the mathematically weaker and inferior tech used by Monero.

plasticmachine 10y ago
Or maybe we're just not buying into cryptography being pushed by a company that has a marketing department.
- anon13 10y ago
  For sure any marketing that they (Zcash) have is no so active as the Monero guys are spreading lies and confusion around. May be we should all abandon the privacy ship, join the Monero guys (no matter its obscure origins by the way) and spread FUD and lies about any better tech like Zcash or others that comes up, right?
  - plasticmachine 10y ago
    By "the Monero guys" you mean the broader technical community that understand security software design? Also, obscure origins are irrelevant when the technology is solid. Take the following examples: TrueCrypt, Bitcoin, MimbleWimble. Are you honestly arguing that TrueCrypt was bad?
    - anon13 10y ago
      By the "Monero guys spreading FUD and lies" I mean exactly that. I have used Monero in the past and consider myself part of that comunity at the time. Even used its predecessor Bytecoin for a while before Monero came up. I have researched a lot and just happen to like and trust Zcash tech much more! May be you should do a bit more research. It is nice to have competing privacy technologies. It is good for privacy loving users and for the advancement of the field. If you like Monero and feel is much better, good for you, use it and enjoy it, this is a free world, but there is no need to lie and confuse people about Zcash.