Shared Coin provides privacy for users' transactions by combining their transactions with other people's.
Shared Coin uses a technique similar to CoinJoin to make transactions private without needing to trust the Shared Coin service. A user's coins never leave their control and therefore it is impossible for them to be stolen or confiscated.
- How does it work?
Shared Coin is a method of making transactions which requires less trust in the service. Shared Coin is based on the CoinJoin concept which acts as a meeting point for multiple people to join together in a single transaction. Having multiple people in a transaction improves privacy by making transactions more difficult to analyse. The important distinction between traditional mixing services is the server cannot confiscate or steal user's coins.
- What logs are kept?
The server does not need to keep any logs and transactions are only kept in memory for a short time. However if the server was compromised or under subpoena it could be force to keep logs. If this were to happen although you haven't gained any privacy you haven't lost any either.
- Are there any fees for shared transactions?
Shared Coin is a free service however a bitcoin network fee of 0.0005 BTC is required.
- How long do shared transactions take?
Between 30 seconds to 5 minutes depending on the number of iterations.
- Is there a maximum transaction size?
The maximum transaction size is 50 BTC.
The user should also remember that Shared Coin can never completely sever the link between the input and destination address, there will always be a connection between them, it is just more difficult to analyse.