Decentralized whirlpool!

[BlackHatCoiner]

I responded to that post, how did you miss it?

That's the insufficient response.

Wouldn't the coordinator be able to gain extra information from pairs of inputs that refuse to participate with each other?

It can conclude that Alice is probably remixing in the coinjoin she refused to join, but that's all. The coordinator doesn't know which one is her remixed coin.

As I previously said, I'm not a Whirlpool expert. My insights stem from observations of technically proficient people who discuss Samourai. I don't completely trust Samourai after reading about what's been said and done throughout the years. Usually, people behind Samourai typically refute criticisms of its ineffectiveness. Could you give me an article that would justify your critique on Whirlpool?

[Kruw]

That's the insufficient response.

How is it insufficient?

It can conclude that Alice is probably remixing in the coinjoin she refused to join, but that's all. The coordinator doesn't know which one is her remixed coin.

As I previously said, I'm not a Whirlpool expert. My insights stem from observations of technically proficient people who discuss Samourai. I don't completely trust Samourai after reading about what's been said and done throughout the years. Usually, people behind Samourai typically refute criticisms of its ineffectiveness. Could you give me an article that would justify your critique on Whirlpool?

Why would I need an article to back up a simple Alice and Bob scenario?

[Kruw]

In Samourai, for example, there is structurally enforced liquidity going into a mix, which means one coin in per mix, without mixing with yourself.

Check out these transactions:

- Alice tx0, 25 premix coins created: https://mempool.space/tx/0640bf6524bdf88655e2547685719482aeaf96f28b2a7a2f0666e7f9c9c01fa3
- Bob tx0, 4 premix coins created: https://mempool.space/tx/c9b43c768b70721387dcb43bc7af29b78615c7f2c44585ff185125763f96944d

In 3 out of 4 of Bob's initial mixes, he was coinjoined with Alice:

https://mempool.space/tx/35c06d50fc67c8e7b175ccca4b8a4bd27cdcaed725e7bf12ad209231a4383e93
https://mempool.space/tx/e202645fbff7fe51ea4bfa874b1c4450d41160ff1cae00b63919a3c1b8819fe7
https://mempool.space/tx/8fc7b5b787459ed23ccb55b2dd7ffd87d2caeb6f92332f94d4478309180f884c

Why is the coordinator continually selecting Alice and Bob to mix with each other?

[BlackHatCoiner]

Why is the coordinator continually selecting Alice and Bob to mix with each other?

Maybe Alice is online more often than others. Or perhaps it just happened, it's normal to expect that sometimes a user might coinjoin with another more often, because the coordinator is supposedly selecting randomly. So, it's a matter of possibilities. Doesn't seem like the coinjoin is weak, though. Bob is simultaneously coinjoining with other people as well.

Why don't you ask in their Telegram? I'm not Samourai contributor. Here you go: https://t.me/SamouraiWallet.

[Kruw]

Maybe Alice is online more often than others. Or perhaps it just happened, it's normal to expect that sometimes a user might coinjoin with another more often, because the coordinator is supposedly selecting randomly. So, it's a matter of possibilities. Doesn't seem like the coinjoin is weak, though. Bob is simultaneously coinjoining with other people as well.

You don't think it looks like the coordinator is Sybil attacking Bob using Alice's coins?

[BlackHatCoiner]

You don't think it looks like the coordinator is Sybil attacking Bob using Alice's coins?

If the Samourai coordinator suddenly turned evil, why would it make it apparent that it is sybil attacking? We have previously discussed that in a malicious coordinator scenario, the coordinator is paying themselves, so the coordinator fee does not discourage them from attacking. Also, the coordinator can select their own remixed coins for free. So, why not create Charlie, Dave and Eric, to make it seem as if many people are used as premixed inputs?

[Kruw]

Also, the coordinator can select their own remixed coins for free.

Exactly. So in order to Sybil attack Bob for free, the coordinator only needs to compromise the xpub address or IP address of Alice.

So, why not create Charlie, Dave and Eric, to make it seem as if many people are used as premixed inputs?

Why would the coordinator do that?