Exchanges are good at blacklisting BTC ,so this means it will be hard for hackers to cash out. Just converting BTC into XMR is not a trivial process, as it needs to go through an exchange. Trustless cross chain transactions are still in infancy .
Yeah but the BTC fee problem isn't trivial. When each "small lot" costs $20 to transfer, your Lambo very quickly turns into a Hyundai
https://ciphertrace.com/twitter-hack-update-blockchain-analy...
https://www.theverge.com/2021/3/16/22334421/twitter-hacker-b...
"(KYC) data associated with the accounts—such as ID, birthday and address—revealing their true identities"
Once the coins entered the mixing services they were gone.
It looks like they got the info from the Texas exchange.
I don't think the TX in that article means an exchange based in Texas. I think TX is abbreviating the word "transaction". Every instance of TX is followed directly by a bitcoin transaction id.
They can technically exist?
Do you mean in the specific case of ring signatures? Or at all?
There are already threshold-signature-based schemes for doing this with ECDSA (though they're very gas heavy at the moment). But none has emerged for ring signatures yet beyond the paper stage.
Yes, assuming sufficiently (not very) expressive transaction signing on said chains. Assume Alice wishes to exchange 1 ABC for Dan's 1 DEF. Alice publishes a transaction for 1 ABC with a UTXO that must be signed by both Alice and Dan. She then provides a zero-knowledge proof that her private key for that signature hashes to XXX. Dan then publishes a transaction for 1 DEF with a UTXO that requires a signature from Alice[0] and a hash preimage of XXX. Alice then pulishes a transaction moving that 1 DEF to her own whereever, which (since second-preimage attacks are hard) contains the private key Dan needs to claim the 1 ABC UTXO.
So this requires that chain ABC supports 2-of-2 (or k-of-n) signature requirements, and that chain DEF supports signature-and-hash-preimage requirements.
This simple protocol is vulnerable to losing money entirely if one party abandons it partway though, but that can mitigated by exchanging eg 0.1 ABC/DEF at a time, or by a more sophisticated exchange protocol.
Edit: 0: using a different key than the XXX preimage.