that's like using a chaumian mint for deposit+withdrawal atomically, right? 🤔
know of any wallet that implements this?
Discussion
Not exactly.
Cashu or Fedimint use ecash as a money warehouse receipt redeemable at par for sats.
In Wabisabi coinjoin the ecash is used as anonymous access rights to the output side of the coinjoin transaction coordination.
The token is not "as good as" sats and it cannot be "redeemed" for sats. Instead it can be redeemed for the right to do an api call in the output registration phase.
A coinjoin coordination can fail frequently and for many reasons. If only one input fails to sign, the transaction is invalid, and even if all sign, it can still get double spent before confirmation.
The merchant doesn't consider himself paid when he receives the wabisabi credential, but only when the final transaction with his output is in the blockchain.
So far nobody has implemented this, but both BTCPay and Wasabi will have this functionality soonish in two weeks.
The coordinator knows the plaintext credential, it's not only known to the sender and receiver?
The trick is, that every time you create a new credential, it's serial number is scrambled/blinded.
And whenever you spend or present a credential, then you must unblind the serial number.
So, the coordinator sees a random blinded cyphertext when the credential is created, and he sees a different random unblinded serial number when the credential is presented.
This is theoretically perfect privacy, meaning Esch credential looks indistinguishably random with the anonymity set of all users of this time period.
Sorry, this was meant for you
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