ERC20 Mixer to transfer fund privatly

Question

I am working on idea to mix erc20 token from one account to many account. i have seen many example but all example has some limitation. like

• you can mix fixed amount.
• Sender can mix one deposit at time.
• if sender send mix request contract send amount to receiver after some time. and he can see in transaction list that from where
  contract received fund.

So is it advisable to create some smart contract which take input from sender and rotate token into 10-20 wallets? and then send it to Receiver's wallet? because in my requirement sender is fix. so only one wallet will deposit mix request and for multiple receiver.

Answer 1

Zero knowledge proofs do take us closer to privacy on public chains. For example see the tornado cash project https://tornado.cash/

Gavin Andresen comments on it here: http://gavinandresen.ninja/private-thoughts

It seems a pretty effective mixer if used carefully.

Answer 2

On ethereum blockchain it does not exist the possibility to transfer funds privately because all the blockchain is public by definition.

Whatever mixing or obfuscation operation is easily reverse engineered by forensic analysis. Moreover it costs a lot in term of gas if you try to adopt algorithm like zsnark.

For this reason no major application doing that are available.

Answer 3

You still need to supply the mixing smart contract the actual address to which you want to transfer the tokens to at some point. And since all (state-changing) transactions to smart contracts are publicly visible in the corresponding block, others could easily infer the sending and receiving parties.