CoinShuffle(++): distributed Bitcoin mixing

CoinJoins allow Bitcoin users to mix funds by collaboratively creating transactions with other participants. This is hugely beneficial to user privacy, since it breaks the typically-deterministic link between inputs and outputs.

CoinJoins are intuitive but powerful. The crux of the idea is that a group of participants must create and sign a transaction for which the value of each user’s outputs is equal to the value of their inputs. In the most common CoinJoin variant, known as an equal-output CoinJoin, each output of the transaction is the same size, excepting the change outputs.