In March we introduced Cahoots within an experimental section of the wallet. Cahoots is a suite of tools to create and handle collaborative peer-to-peer CoinJoin transactions between two wallets. Unlike our Whirlpool CoinJoin service, Cahoots transactions do not require a blinded coordinator server to function. A bare bones implementation of PayJoin known as Stowaway and an enhanced STONEWALL that we named STONEWALLx2 were added to the wallet for advanced users to help test the bleeding edge of privacy enhancing transactions.
We are very excited to release these privacy features to the wider public as of version 0.99.85. We have created what we hope is an intuitive and friendly interface for performing an inherently complex task. As usual, these features are a work in progress and your feedback will help refine the usability as development progresses. With that all out of the way, let us dive right in.
apk hash sha-256 of version 0.99.85 : 1746c78c407f61c7794e4096dc014978d22f309796b9a5268c0e54d5d7ca5751
Toggle Cahoots before sending
You invoke Cahoots from the Send screen of your wallet. You will be asked to choose between two types of Collaborative transaction.
This transaction makes use of a collaborators UTXO set in addition to your own to compose the transaction. The result is a high entropy “mini CoinJoin” transaction. STONEWALLx2 is a great way to quickly mix on demand when sending to any third party by enlisting the help of a privacy conscious friend. In this transaction, both the sender and the collaborator split the miner fee down the middle.
Bob wants to send to Charlie, so he gets Alice to STONEWALLx2 with him.
Stowaway is designed to blend in and look like a typical bitcoin transaction. Outside observers will not be able to tell that the Stowaway transaction is a two person CoinJoin. Additionally the true amount sent is not revealed on the blockchain. Unlike STONEWALLx2, Stowaway transactions can only be sent to the same person you are collaborating with. This makes Stowaway a great option for mixing when paying your privacy conscious friend. In this transaction the sender pays the full transaction fee.
Bob wants to send to Alice, so they do a Stowaway together.