# Autonomous Ethereum mixers by Ivan Bogatyi (Devcon5)

- Channel: [Devcon](https://streameth.org/devcon)
- Date: 2020-10-09
- Duration: 06:28
- Topics: blockchain, smart contracts, distributed ledger, ethereum, Science & Technology
- Watch: https://streameth.org/watch/yt-qNGskbgOY-E
- YouTube: https://www.youtube.com/watch?v=qNGskbgOY-E

## Description

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https://archive.devcon.org/archive/watch/5/autonomous-ethereum-mixers

I demonstrate how to build a profitable, self-sustaining Ethereum mixer. I use zkSNARKs as the core mixer mechanism [1], and invest the shielded money pool into a risk-free DeFi application to earn interest [2].  The mixer complies with Vitalik's interface proposal [3].
The general privacy setup is similar to ZCash: a "shielded" pool, which contains all the ETH deposited by people who desire anonymity, and "notes" that can be withdrawn without revealing any connection to the deposit transaction. Importantly, this provides K-anonymity for K → ∞, unlike ring signatures or MimbleWimble, providing K-anonymity for K [less than] 15 (ring signature size in Monero, block size in MimbleWimble) and thus prone to several attacks [4, 5].
The pool of ETH deposited into the mixer and awaiting withdrawal is supplied into the Uniswap WETH converter (~4%/year ROI). Unfortunately, that revenue cannot be supplied to the users, since the exact amount would give away precisely when the deposit was made. On the other hand, it can be used to subsidize infrastructure and "keepers" that made the withdrawal transactions for clients – a known problem for all previous mixer designs.
[1] https://github.com/barryWhiteHat/miximus
[2] https://zumzoom.github.io/analytics/uniswap/roi.html ETH-WETH pair
[3] https://hackmd.io/@HWeNw8hNRimMm2m2GH56Cw/rJj9hEJTN?type=view
[4] https://ipfs.io/ipfs/QmWYTeggKeL8xBitA8uQWAaNDWfFrUHXAxBXkvmnisdDw7
[5] https://eprint.iacr.org/2019/455.pdf

Speaker(s): Ivan Bogatyi
Skill level: intermediate
Track: Developer Infrastructure
Keywords: technical

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Devcon is the Ethereum conference for developers, researchers, thinkers, and makers. 
Devcon 5 was held in Osaka, Japan on Oct 8 - 11, 2019.
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## Transcript

[Applause] hi everyone my name is Yvonne and I've been do a quick overview of tough to Middletown became a mixer with the specific focus on building one that is completely anonymous and does not require human interaction or human subsidies so if you look at these see themselves right now many of them are not 100% decentralized they tend to require either a price key remediate a we layer that's subsidized by some company maybe one exception will be you swap that exists on chain and requires pretty much no interaction and so let's see how close we can get back to the gold standard yes so first of all there's if you mixing technologies that exist this days the first one is enjoying the statues in Bitcoin discipline for example in the wasabi wallet and it's also used in memorable and grim if you've been following the project then there is equally based which is used in Manero and finally there's always vertical three based verticals of the of investment wanna see cash and there's if you if you mix there's built on top of theft that vertical as well including it makes the most sense or not attached so quick overview of all three who join is basically instead of two people doing two different two different transactions they come together for the purposes of climbing up helping each other be anonymous and the merge that into one single transaction so for example here if time is a drug dealer and bombing LSU's who enjoying it's impossible to know whether LS or ball being the drug dealer so they kind of give each other this possible deniability the problem of that is your anonymity status very low it says maybe white people doing the despite people helping you be slightly more anonymous but that's not quite good enough the next thing is the decrease of privacy which is using Manero the ad is you can use a on chin Beauty EXO and pretend that that would've been your input so basically every transaction has maybe attempt to 15 sources only one of them is video the rest of them we could like not even know that they've been used in the immunization so that's that's quite a lot better and then there's a separate technique for fight for fighting the Imams behind those transactions where you do bit by bit encoding but decoy protocols have suffered from punch of attacks before long story short there's risks of repeated interactions so if the same person please the same drug dealer a few times in a row there's going to be multiple part multiple paths in the transaction graph the from that person to the drug dealer that's pretty bad point being kind of quiet process of elimination we arrive at zero knowledge Merkle tree based mixers as the only the only way to achieve maximum an amenity and here the ad is the sugar pool that keeps all the money that wants to participate in the analyzation and no one knows who they swim with in the pool and then you deposit into the pool we for wild-animal draw and so that is kind of the most private wave of anonymizing your points pretty so what are the components that we Zeki start mixer first you need a core smart contract that that takes that money and processes deposits and withdrawals typically requires I trust it set up not necessarily anymore that also ZJ starts then you need to generate the immortal Phoebe's for deposit basically thus you'll hear that's the first arrow of continually pool they need to exit through the pool that requires about sixty seconds and then you need to send up those transactions in turn the VG is every single piece of those components chameleons paunchy by their own ETA and one for a DFS the first part is sending the transactions so that has to be OB layers sponsoring all that and there's first off you need to differentiate between the person helping you they're all and the recipient address so that you can draw to clean addresses and have fifties handle for you so how do we sponsor that one we could deposit money to compound to into the you swap as liquidity pool or we could take a feel and so if you do a quick cultivation you swap will sponsor a transaction at 800,000 guess which is roughly near its price up 2.25 we which to those who uses here you know this is very little this this will never go through on chain actually and then if you deposit die which gives you much higher interest rate that's up to four we and then if you take 1% or 5% tea the that's much more realistic so long story short for immunization and Long's over roughly one either you need to pay roughly 5% fee to sponsor the role and make the layer sustainable thank you some more things to to look at that [Applause] you