[HN Gopher] Tornado cash takedown and its repercussions
       ___________________________________________________________________
        
       Tornado cash takedown and its repercussions
        
       Author : whoami_nr
       Score  : 42 points
       Date   : 2022-08-09 20:06 UTC (2 hours ago)
        
 (HTM) web link (rnikhil.com)
 (TXT) w3m dump (rnikhil.com)
        
       | MBCook wrote:
       | So the article says the blockchain is, by design as a public
       | ledger, a privacy nightmare.
       | 
       | And we have to use it (for some unstated reason).
       | 
       | So the only solution must be to enable money laundering so people
       | can get their privacy back.
       | 
       | My take: that seems kind of backwards. How about we just don't
       | use the thing that purposely exposes everyone data? If people
       | want privacy then that seems like a design flaw.
       | 
       | Enabling (maybe limited) money laundering is not a good solution.
       | It's a very odd band-aid on the real problem.
       | 
       | This is a false dilemma. We have more choices than "enable money
       | laundering" and "no one has privacy".
        
         | AnthonyMouse wrote:
         | > This is a false dilemma. We have more choices than "enable
         | money laundering" and "no one has privacy".
         | 
         | Which other choice is there? AML as-implemented is literally a
         | policy that says you can't have digital transactional privacy,
         | which is the only reason privacy technologies violate it when
         | no other lawbreaking occurs.
         | 
         | And it has <= 0.2% effectiveness and high compliance costs.
         | 
         | https://www.tandfonline.com/doi/full/10.1080/25741292.2020.1...
         | 
         | It's a total failure and it's inexplicable that anyone who
         | understands it would defend it.
        
           | MBCook wrote:
           | I'm fine with AML. I'm not someone who is a privacy
           | absolutist and thinks it shouldn't exist.
           | 
           | My #1 concern is privacy from other people in my banking
           | transactions. You know those Twitter accounts that post
           | everywhere celebrities fly? No one should be able to do that
           | for what I buy. Bitcoin gives anyone that information _by
           | design_. I don't like that.
           | 
           | But again, I think the article's solution is attacking the
           | wrong problem.
        
         | Zamiel_Snawley wrote:
         | Would you say strong encryption vs government backdoored
         | encryption is a false dilemma too?
         | 
         | I think these are analogous issues, and we have seen several
         | times that if there is a backdoor, you can not keep it so only
         | the "good guys" have the key. So this is a true dilemma, you
         | can either have strong encryption or backdoored encryption.
         | 
         | I believe the financial privacy vs money laundering is also a
         | true dilemma. If you have privacy, money laundering is trivial.
         | If you can not money launder, you do not have privacy.
         | 
         | Additionally, just because you trust the financial institutions
         | you deal with does not mean you have privacy.
         | 
         | You have more privacy than you would on a public ledger, but
         | some people have privileged access and can see all your
         | financial information.
         | 
         | This lack of transaction privacy does enable censorship[1].
         | 
         | However, I think most people are willing to exchange their
         | privacy for anti-money laundering.
         | 
         | [1] https://www.eff.org/deeplinks/2017/03/payment-processors-
         | are...
        
         | baobob wrote:
         | If a technology makes money laundering a prerequisite to
         | privacy, the technology itself is bullshit. There's no need to
         | spend words to justify this further.
         | 
         | In no other industry would you find for example, "we made a
         | better hammer, but when you use it to drive nails as a minor
         | side effect, it may/may not fund the abuse of children and
         | development of nuclear weapons by rogue states"
         | 
         | If you truly believe in privacy, it's okay to simply say the
         | technology is fundamentally broken by design and seek a better
         | alternative.
        
           | stickfigure wrote:
           | That $5 hammer you bought at Harbor Freight unquestionably
           | contributes in a tiny way to human rights abuses by an
           | authoritarian regime.
        
           | celticninja wrote:
           | That's a terrible analogy.
        
       | colinsane wrote:
       | > What happens to the FOSS developers who contributed to the
       | project? Are they sanctioned as well?
       | 
       | devs were mostly anonymous, IIRC. Coindesk says "Tornado Cash
       | developer Roman Semenov's GitHub was suspended." [1]
       | 
       | > What will happen to the tainted money? This figure is about
       | 400M$. I expect a secondary market for TCtETH (Tornado cash
       | tainted ETH)
       | 
       | indeed. the feds haven't seized any money. the 10,000s of TC
       | users still have anonymized possession of decent sums of money
       | and have effectively been told "you can't legally use this for
       | goods and services". have the feds just created a bunch of $1000
       | coupons for DNMs?
       | 
       | > What happens to the protocols/pools/(d)apps which interacted
       | with it?
       | 
       | contract still live, i assume. i think it was governed by a DAO
       | so if they haven't/don't hurry up and lock that down there's risk
       | of a malicious takeover as the TORN token devalues. if you
       | blacklisted everything that these tokens interact with you'd
       | blacklist like 10% of crypto. AMMs and bridges are in some sense
       | just a much more diffuse tumbling service. i guess it works for
       | now because most people running Ren nodes (for example) don't
       | understand that they're helping people launder, whereas the TC
       | service is much more in-your-face.
       | 
       | Tornado Cash published their UI a month ago. their GitHub's been
       | taken down but i expect mirrors will surface. it should be
       | totally possible to keep using the service -- expect
       | significantly decreased liquidity -- and the fun part (for me)
       | will be to sit and watch to what degree the decreased normie use
       | of TC kills the thing v.s. just slows it down.
       | 
       | the GitHub ban is a warning to me though. i'm in (non-crypto)
       | circles where we largely host our own repos, but few of us
       | publicly mirror the software we build upon. makes me think i
       | should start doing so in advance.
       | 
       | [1]: https://www.coindesk.com/policy/2022/08/08/crypto-mixing-
       | ser...
        
         | carlosdp wrote:
         | > contract still live, i assume. i think it was governed by a
         | DAO
         | 
         | Just chiming in to make it clear that the protocols that have
         | to do with the core service are not governed by a DAO and are
         | fully immutable. Nobody can change or shutdown those smart
         | contracts without the blockchain itself manipulating things,
         | which is for all intents and purposes impossible.
        
         | FpUser wrote:
         | >"the GitHub ban is a warning to me though. i'm in (non-crypto)
         | circles where we largely host our own repos"
         | 
         | I am a small fish that develops software products for clients
         | and for my own company. The chances of me being punished by
         | Github are probably close to 0 since I do not do anything even
         | remotely related to money, politics and other "hot and exiting"
         | areas. Still unless explicitly requested by client I always
         | host my own stuff either on my premises or on rented dedicated
         | servers from OVH and Hetzner. The whole idea of someone else
         | controlling my assets drives me up the wall and I am trying to
         | avoid it as much as reasonably possible.
        
           | frozencell wrote:
           | Do you use OVH because it hosts(Ed) Wikileaks?
        
         | [deleted]
        
         | JumpCrisscross wrote:
         | > _have effectively been told "you can't legally use this for
         | goods and services"_
         | 
         | No, they haven't. When the Russian central bank was sanctioned,
         | everyone who's done business with them didn't lose the dollars
         | they were paid. They're under more scrutiny, when they spend
         | any of their dollars, because they were proximate to a
         | sanctioned entity. But the funds are still theirs.
        
         | chrisco255 wrote:
         | > contract still live, i assume. i think it was governed by a
         | DAO so if they haven't/don't hurry up and lock that down
         | 
         | Most smart contracts are deployed in such a way as to be
         | immutable. They can also be cloned trivially. The source has
         | already been backed up to IPFS.
         | 
         | They might as well ban elliptic curves.
         | 
         | Also, someone already used TC to send 0.1ETH to dozens of
         | celebs such as Jimmy Fallon and Dave Chappelle, because crypto
         | works like email. You can't prevent someone from sending
         | something and you can't prove it was or wasn't them that
         | initiated it.
        
           | amluto wrote:
           | But you can refuse to allow those tainted ETH to be exchanged
           | for anything off the Ethereum blockchain.
        
             | chrisco255 wrote:
             | If I send you 0.1 ETH and your wallet already had 8.76 ETH
             | then you engage in 100 transactions and trades and in the
             | process you zero out the account a few times and you refund
             | the account a few times. Which 0.1 ETH is sanctioned? At
             | which address? When it was swapped in a Uniswap liquidity
             | pool for a defi token which was provided as collateral on
             | Aave then borrowed against in RAI only to be swapped for
             | NFTs that were flipped for a profit and distributed to 27
             | different addresses?
        
               | spinny wrote:
               | I believe that the most used is the FIFO method
               | (https://arxiv.org/pdf/1906.05754.pdf)
        
       | fabiofzero wrote:
        
         | fabiofzero wrote:
        
           | glerk wrote:
        
           | klyrs wrote:
           | I lean anti-crypto but I flagged you. This kind of comment
           | doesn't belong here.
        
       | paulpauper wrote:
       | _What will happen to the tainted money? This figure is about
       | 400M$. I expect a secondary market for TCtETH (Tornado cash
       | tainted ETH)_
       | 
       | This is why crypto was never fungible or useful for privacy
       | purposes. Gold and other precious medals can be melted. Crypto
       | can never be seamlessly mixed. No matter how hard you try,
       | transactions and trails can be reconstructed. The only way to mix
       | is to generate a huge amount of noise.
       | 
       | This was inevitable. For the past 2 years or so years hackers
       | would process their loot with Tornado. There is no way the govt.
       | would stand for this. It's similar to how the Wanna Cry hack , in
       | 2017, made KYC much more common because the hackers used
       | exchanges to convert stolen BTC into monero. All it takes is a
       | handful of people to abuse a service for it to be tainted/ruined
       | for everyone else.
        
         | aaaaaaaaata wrote:
         | > generate a huge amount of noise.
         | 
         | Monero?
        
         | chrisco255 wrote:
         | > Crypto can never be seamlessly mixed. No matter how hard you
         | try, transactions and trails can be reconstructed.
         | 
         | Yes, you can. Particularly with zero knowledge proofs and zero
         | knowledge rollups.
        
           | giblfiz wrote:
           | Yep, which is actually specifically what tornado.cash was. It
           | was a zk based mixer.
           | 
           | As you say: You absolutely CAN seamlessly mix crypto, but it
           | will show a point in it's history where it says "this is
           | where the crypto was seamlessly mixed"
        
           | paulpauper wrote:
           | I should have said "most". This shows how hard it is even
           | when using various methods such as cross chains:
           | 
           | https://www.wired.com/story/bitcoin-seizure-record-doj-
           | crypt...
        
         | carlosdp wrote:
         | > "Crypto can never be seamlessly mixed"
         | 
         | > "The only way to mix is to generate a huge amount of noise"
         | 
         | These are directly contradictory statements...
        
         | peyton wrote:
         | > The only way to mix is to generate a huge amount of noise.
         | 
         | That simply isn't true.
        
         | kragen wrote:
         | ZCash, Monero, and MimbleWimble implementations such as Grin
         | are seamlessly mixed; it's not a problem with all cryptocoins,
         | just some. I think it's a much bigger problem for Ethereum than
         | for Bitcoin, too, because Bitcoin doesn't have accounts, just
         | unspent transaction outputs.
         | 
         | The non-blinded nature of some blockchains has always been a
         | theoretical risk to the fungibility of their cryptocurrencies,
         | and there have been isolated cases of blacklisting. Today that
         | threat has suddenly materialized in a very significant way.
         | Very likely that will create pressure toward cryptocurrencies
         | with strong anonymity.
        
         | TarasBob wrote:
         | Crypto can ve seamlessly mixed. That's exactly what Tornado
         | does.
        
           | paulpauper wrote:
           | Yes, it breaks the link from the original addresses to the
           | new one, but it shows as coming from Tornado Cash. That's why
           | this sanction is such a big deal. There was a paper that
           | showed that Tornado cash privacy can be possibly compromised
           | by studying transaction attributes https://link.springer.com/
           | chapter/10.1007/978-981-16-9229-1_...
        
         | whatisweb3 wrote:
         | > No matter how hard you try, transactions and trails can be
         | reconstructed.
         | 
         | Except the opposite is true. Tornado cash protocol is working
         | well enough in its privacy features that the US government
         | feels the need to threaten any business touching it directly or
         | indirectly.
         | 
         | Imagine you made this argument for E2EE. The US government can
         | sanction and ban the use of Matrix and all other E2EE chat
         | protocols making it very difficult for users to engage with
         | them - but this does not mean the cryptographic protocols are
         | failing to provide privacy and security.
        
       | olalonde wrote:
       | > What will happen to the tainted money? This figure is about
       | 400M$. I expect a secondary market for TCtETH (Tornado cash
       | tainted ETH)
       | 
       | 1) The sanctions only apply to U.S. persons.
       | 
       | 2) My understanding is that it's fine to accept "tainted" ETH as
       | long as it doesn't directly come from one of the Tornado Cash
       | contract addresses[0].
       | 
       | [0] https://home.treasury.gov/policy-issues/financial-
       | sanctions/...
        
         | sofixa wrote:
         | > The sanctions only apply to U.S. persons
         | 
         | Are you sure? That's usually not how US sanctions work - they
         | claim extraordinary jurisdiction. E.g. BNP Paribas were fined
         | for transacting with Iran even though they're a French bank and
         | France has not sanctioned Iran (to that extent).
        
           | olalonde wrote:
           | That's what the OFAC press release explicitly claimed[0].
           | There are plenty of countries outside the U.S. doing business
           | with Iran by the way, see this thread[1]. The press release I
           | found on the Paribas case states that they were using the
           | U.S. financial system to violate sanctions[2].
           | 
           | [0] https://home.treasury.gov/policy-issues/financial-
           | sanctions/...
           | 
           | [1] https://news.ycombinator.com/item?id=32054821
           | 
           | [2] https://www.justice.gov/opa/pr/bnp-paribas-sentenced-
           | conspir...
        
       | macawfish wrote:
       | TCtETH is not a thing... Ethereum is not using a UTXO model and
       | even if it was some serious off chain analysis would be required
       | to make something like that work
        
       | jeroenhd wrote:
       | > This also might be the first time where a piece of code got
       | sanctioned.
       | 
       | It's not, though. The project got sanctioned and by extension the
       | services it provides. The blockchain implementation of said
       | service is rather unique, but I don't think this is technically
       | any different from projects like Popcorn time being sued/shut
       | down despite their p2p systems.
       | 
       | The difficulty with smart contracts is that it's hard to take
       | those services down. After all, you can't take a smart contract
       | out of ethereum. The legal ramifications of this are interesting:
       | the undeletable nature of blockchains and their capacity to store
       | arbitrary data or execute arbitrary code could taint the entire
       | blockchain when bad actors unleash services that cannot possible
       | be taken down, causing anyone participating in the blockchain
       | system to be an accomplice. Or perhaps the governments of the
       | world will look at this more pragmatically and simply consider
       | the contract dead, only sanctioning new people who call upon the
       | contract to execute transactions.
       | 
       | This indestructibility of the blockchain is often sold as a
       | benefit, a way to stick it to the government, but the real world
       | doesn't care about your technical implementations when the police
       | tells you to shut it down. Designing a system that you cannot
       | control or shut down may not be a great idea, especially if
       | interactions with said system are logged permanently and
       | publicly.
        
         | carlosdp wrote:
         | > It's not, though... any different from projects like Popcorn
         | time being sued/shut down
         | 
         | An OFAC sanction is orders of magnitude more serious than
         | Popcorn Time being taken down via DMCA requests and lobbying. I
         | don't think that's a fair comparison.
        
           | rhodorhoades wrote:
           | You initially say it's not any different than Popcorn time,
           | then go onto explain all the reasons why it's completely
           | different than popcorn time.
        
           | brundolf wrote:
           | Seems like a better example would be when cryptography in
           | general used to be subject to arms regulations https://en.m.w
           | ikipedia.org/wiki/Export_of_cryptography_from_...
        
         | tick_tock_tick wrote:
         | > After all, you can't take a smart contract out of ethereum
         | 
         | You absolutely can. Ethereum has forked in the past to alter
         | inconvenient data / network state.
         | 
         | I've not looked at there contract but contracts can kill
         | themselves if setup for it. See the SUICIDE opcode.
        
           | whatisweb3 wrote:
           | Ethereum has hard forked once with the DAO. It needs a
           | significant divergent of opinion - like 10% of all miners
           | splitting off into their own network, client tooling,
           | platforms, and ecosystem.
           | 
           | It is not something that can be done on a whim and can't
           | happen every time the US adds a new address to their
           | sanctions list.
        
             | sp332 wrote:
             | _Technically_ , Ethereum has hard forked multiple times,
             | for example to avoid "ice age" difficulty cliffs that were
             | supposed to force the switch to proof-of-stake multiple
             | times now. But the vast majority of miners, and
             | importantly, the currency exchanges, have all been on the
             | same side of those forks.
        
               | viscanti wrote:
               | The contention was that it can happen to remove/censor
               | contracts or transactions, not that forks don't happen
               | more broadly. It seems the point still stands that there
               | was a single fork around the DAO and the odds of anything
               | like that again are basically zero.
        
           | TarasBob wrote:
           | No. Ethereum has never forked any inconvenient data or
           | network state.
        
             | idiotsecant wrote:
             | I am a huge fan of Ethereum but I think the DAO hack fork
             | unquestionably falls into this category.
        
               | TarasBob wrote:
               | Ethereum was only a few months old at that point and you
               | could say it was alpha software with training wheels.
        
           | idiotsecant wrote:
           | Don't you think the type of contracts that are likely to be
           | sanctioned by world governments are exactly the type of
           | contracts that will be unlikely to implement a suicide
           | method?
        
       | game-of-throws wrote:
       | For those who think this is a good thing: can you explain why
       | people should have access to HTTPS and Tor (web privacy), PGP and
       | Signal (communication privacy), but not Tornado Cash (financial
       | privacy)?
        
         | brk wrote:
         | I'm not an expert on this, but I think it comes down to Tornado
         | being primarily associated with fraud/crime related
         | transactions. Similar to Silk Road being shut down while Amazon
         | was left to grow. Both had some percentage of fraudulent
         | products, but only one was viewed as existing primarily to
         | facilitate fraud/crime.
        
           | Zamiel_Snawley wrote:
           | According to this source, about ~20% of the value that has
           | gone through tornado cash is thought to be criminal proceeds.
           | 
           | [1] https://techcrunch.com/2022/08/08/treasury-tornado-cash-
           | laun...
        
           | TarasBob wrote:
           | No. Tornado is not primarily associated with fraud or crime.
        
           | whatisweb3 wrote:
           | Tor is primarily associated with crime. Doesn't mean we
           | should throw away privacy tools and submit to surveillance
           | state.
        
             | ricochet11 wrote:
             | id take the bet that 10x more crime happens over WhatsApp
             | chats than tor and ethereum combined
        
         | [deleted]
        
       | yuan43 wrote:
       | This is why you don't publish addresses. Ever. You use them once
       | and toss them. Any system that requires otherwise is subject to
       | the same fate as Tornado eventually.
       | 
       | That said, blacklists are an asinine idea cooked up by people
       | eager to score PR points. All it takes is one single conduit out
       | to render the list useless in achieving its stated goal.
        
       | potatototoo99 wrote:
       | The US has been hostile to the businesses around crypto for some
       | time now, this is just one more reason to keep it away from the
       | eyes of the US govmt if you are in their jurisdiction.
        
       | MisterBastahrd wrote:
       | Am I supposed to feel terrible for people who got caught up in a
       | money laundering scheme because they worked on the technology but
       | maybe didn't actually launder any money? Because that's not going
       | to happen. Anyone with a brain knew what Tornado Cashs' primary
       | use case was, and they also had to know that governments are not
       | fond of money laundering schemes. Leopards eat faces all the
       | time.
        
         | chrisco255 wrote:
         | Primary use case is privacy. Just like "right to be forgotten"
         | in Europe, as part of GDPR, which is a law on the books.
         | Blockchains cannot forget, and everything is traced, so the
         | only way to be forgotten on chain is via a mixer of some sort.
        
           | tick_tock_tick wrote:
           | That is a good point at present most blockchains are almost
           | certainly illegal in the EU. Wonder which country is going to
           | jump on that first.
        
           | amanaplanacanal wrote:
           | So perhaps don't do business on chain if you are looking to
           | be anonymous.
        
             | lowkey wrote:
             | Also stay off the internet if you don't live in the EU and
             | wish to stay anonymous.
        
         | paulpauper wrote:
         | From what I understand, the us govt. cannot just prosecute
         | people for using tornado cash, because privacy in and of itself
         | is not a crime. It means however, that exchanges will probably
         | scrutinize it much more. It compromises the fungibility of
         | Ethereum tied to tornado cash.
         | 
         | --edited for spelling --
        
           | JumpCrisscross wrote:
           | > _exchanges will probably securitize it much more_
           | 
           | Scrutinise?
        
         | ricochet11 wrote:
         | From the analysis being shared around, ~10% of transactions via
         | TC were from hacks, the rest _the vast majority_ are
         | individuals protecting their privacy. as in their human right
         | to do. its a block of code that uses cryptography to hide
         | information. like tor or https. there are many many valid
         | reasons to do this.
         | 
         | i know hackernews doesn't like crypto, but come on maybe
         | question why we are fine with this government overreach? maybe
         | question is this a trend we want to support as "hackers"? could
         | we consider the fact that all governments in the world have a
         | history of abusing surveillance to harm their citizens? you
         | know not long ago i could be locked up for being gay, maybe
         | standing up for cryptography is a good thing to do?
         | 
         | but oh no bitcoin is icky good job government protec me from
         | the bad ideas.
        
           | colinsane wrote:
           | > the vast majority are individuals protecting their privacy.
           | 
           | i get your point but i don't know if it's true. on various
           | occasions, i've wanted to (1) anonymize my funds before
           | sending them to a discreet cause and (2) generate return on
           | the funds i hold long term. for (1) i specifically avoid TC
           | because going through a tumbler points a huge target of "this
           | is suspicious activity", thereby drawing more attention to me
           | specifically (attention isn't good for privacy). for (2) TC
           | became an appealing place to park ETH particularly after ETH-
           | denominated yields plummeted during this last DeFi crash (TC
           | pays fees to the mixing pool). do we know how much of that
           | "90% of non-hacked funds" involved in TC were provided by
           | privacy advocates v.s. good ol' capitalists seeking returns
           | from laundering?
        
       | whatisweb3 wrote:
       | The US sanctioning Tornado Cash and the resulting repercussions
       | is deeply concerning. Whether or not you like crypto, you should
       | not be supporting this if you are a researcher, academic,
       | technologist, cryptographer, or privacy advocate. The code for
       | Tornado Cash is a series of cryptographic and mathematical
       | functions that can be repurposed for a variety of applications
       | unrelated to privatizing user wallets. The protocol itself is
       | designed for one reason: to give users privacy through end to end
       | and zero knowledge cryptography.
       | 
       | Allowing it to remain open source and accessible as a tool for
       | blockchain privacy and codebase for cryptographic research is a
       | net benefit for the entire world.
       | 
       | A comparison would be that US decides to sanction the open Matrix
       | protocol along with any user, developer, source host, or sponsor
       | that has ever contributed to it in the past - because it can
       | facilitate end-to-end encrypted terrorist communication.
        
         | twoodfin wrote:
         | In US Constitutional law, bare communication has
         | _significantly_ greater protections than the non-speech-related
         | transfer of money from one party to another.
        
       | TarasBob wrote:
       | Let's say you're a business that accepts crypto and what if
       | someone sends you ETH or some coins like USDC. Is it your job to
       | check that these coins didn't come from Tornado? It's quite hard
       | to do that. What if account A got their ETH from Tornado, then
       | sent it to account B, which then exchanged the ETH to USDC on
       | Uniswap, which then sent the USDC to account C, which then sent
       | the USDC to you.
       | 
       | This is a problem for Bitcoin as well. What if someone got ETH
       | from Tornado. Then converted the ETH to renBTC
       | (https://renproject.io/) on Uniswap. Then converted the renBTC to
       | BTC. Are those Bitcoins now somehow tainted?
       | 
       | This new law makes crypto essentially unusable (at least for US
       | persons).
        
         | paulpauper wrote:
         | _Are those Bitcoins now somehow tainted?_
         | 
         | Possibly. It depends on who the recipient is. Coinbase may not
         | want the coins but others will not care.
        
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