Quote from: garlonicon on February 20, 2022, 08:34:42 PM

I think the Lightning Network is one of the best mixers I know about.

ChipThunder - A Lightning micro-mixing service proposal

ChipMixer is an easy mixer to use, which gives the users a privilege; time traveling. It hands them over the Unspent Transaction Outputs' private keys, which were funded prior their deposit and can be, therefore, withdrawn whenever they want, in the future. A smart privacy technique is to not withdraw at the same time they deposit, because it makes their trace easier to be achieved.

For example,

Bob sends 1 mBTC to ChipMixer in 2021-09-11 07:14 (block 700,000).
Bob waits for 1 confirmation.
Transaction is confirmed in 2021-09-11 07:15 (block 700,001).
Bob receives a 1 mBTC worth of chip that was funded a month ago, in 2021-08-09 22:13 (block 695,000).
Bob withdraws his 1 mBTC to his wallet, and the transaction gets confirmed, right after, in block 700,002.

Bob's past-money have no connection with ChipMixer's 1 mBTC chip, but he's made it a lot easier to become traced. Someone who's analyzing the chain can see that at around the same time our friend Bob sent 1 mBTC to an unknown address, one of the ChipMixer's outputs of the same value, which were funded long before Bob deposited, was spent. So, it's rational to assume that Bob is likely to own this new output. And that's before ChipMixer uses Bob's past-money to create new chips and make it even more obvious.

A solution to the above problem is to just not spend at the same time you deposit. For instance, if Bob spent the chip about 2 weeks later, he'd have enhanced his privacy by a lot. However, this solution is pruned to losing self-custody. Bob is, essentially, forfeiting his ownership for 2 weeks, something that might discourage him do so.

ChipMixer has gained everyone's trust, and I've left money there for weeks to accomplish privacy strength, but trust is just contradictory with the protocol. The more time you leave money to a third-party, the greater are the risks. Therefore, we have a problem in the way we will gain the benefits of time traveling without the risks. Here it comes, ChipThunder.

How does it work

If Bob has a properly running Lightning node, with non-zero receiving capacity, he can choose to receive the money via Lightning, making his 1 mBTC record obscured. What's, contemporaneously, positive is that ChipMixer has a lot of chips leftover for future mixing, that can be used, until then, as sending capacity of their private Lightning node. If Bob prefers having BTC instead of LN-BTC, he can send it back once he feels ready for on-chain chip withdrawal.

Mixing example #1

Bob deposits 1 mBTC on-chain.
Once the transaction is confirmed, Bob chooses to withdraw the chip via Lightning.
Bob receives 1 LN-mBTC instantly.
Bob can now spend the bitcoin freely, knowing he's respected both the principles of self-custody and privacy.

Mixing example #2

Bob deposits 1 mBTC on-chain.
Once the transaction is confirmed, Bob chooses to withdraw the chip via Lightning.
Bob receives 1 LN-mBTC instantly.
Bob prefers to have the bitcoin on-chain, so he sends it back to ChipMixer.
Bob can now spend his 1 mBTC chip freely, again, knowing he's enhanced his privacy without infringing self-custody.

What do you think?