Remember that these are confined to the network layer of Bitcoin:

1. With BIP156, your IP address will no longer be tied to your personal transactions from the perspective of connected Bitcoin nodes.
2. With BIP151, all relayed transaction data will be encrypted from the perspective of someone analysing internet traffic (but connected Bitcoin nodes will still see the transactions unencrypted).


Neither of those BIPs will change the ability to analyse transactions on the blockchain



No, Musig Schnorr makes using multiple inputs less expensive. This only incentivises coinjoins, it does not make them any more private.

edit: Musig is for threshold based multisig that is safe to use with signature aggregation (without Musig, the last person adding their sig to an n of n aggregated public key could cheat by throwing out all the previous keys and replacing them with 1 key that belongs to them, and pretend that all the previous people's keys are aggregated together into it, so they can steal everyone's money). And so Musig doesn't have anything to do with privacy or anonymity on the blockchain either

Yeah, I always suspected that these mixing services wouldn't stand up to a concerted traffic analysis.

Top notch work, I bet some folks are sweating a bit right now...these tracks never fade.

You're right, I don't know how I skipped over that



I see your point: multi-sig using Musig looks like a 1 input transaction when spending from a Musig address, regardless of how many signers are needed to pass the threshold. But the way I understand it, it's Schnorr's additive keys property that confers that quality, and not Musig per se.

Certainly, Musig is designed at least in part to prevent the attack I described in my previous post, an attack which is a consequence of using additive public keys to generate the public key for a multisig address. So it seems logical that it's Schnorr that's improving multisig privacy, and Musig that mitigates the risks of using Schnorr signing for a multisig address.

Hi madu, thanks again for giving us the time and patience to work out an article on your thesis and findings. It's published now as a feature here and I'm glad to see it's also mentioned on Wasabi Wallet's succinct article on centralised mixing services.

Like others, though, I'm still keen to see if your same techniques would have worked for ChipMixer. I believe it's been one of the few centralised mixers to have innovated on the techniques. Any success breaking it would prompt even more innovations (in fact, happy to provide test samples if you need!).