Shared Coin

Share your coins, not your privacy.

Shared Coin provides privacy for your transactions by combining your transaction with other people's.

Shared Coin uses a technique similar to CoinJoin to make your transactions private without needing to trust the Shared Coin service. Your coins never leave your control and therefore it is impossible for them to be stolen or confiscated.

Free & Open Source

The Next Generation of Bitcoin Privacy

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 your coins.

There is more to learn about Shared Coin

Click to read more FAQs

  • 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 your 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.

  • What does a Shared Coin transaction look like?

    A Shared Coin transaction will look something like this. As you can see multiple inputs and outputs make the determining the actual sender and receiver more difficult.

  • 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.

  • Is there a minimum transaction size?

    We recommended you do not send transactions less than 0.01 BTC

  • 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 to use it safely without accidently leaking info?

    - Tor can prevent leaking of information through your ip address.

    - Sending coins to or from tagged addresses reduces privacy.

    - When creating a Shared Coin transaction your browser generates a number or temporary/intermediate addresses. The balance of these addresses is not checked on blockchain.info itself unless the "Recover Intermediate Addresses" button is used. Looking up the balance of these addresses is an information leak as if blockchain.info was keep logs it would show you had an interest in these addresses. So don't use the "Recover Intermediate Addresses" tool unless there has been an error with a transaction.

  • What limitations does it have?

    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.

  • Is Shared Coin Open Source?

    Yes. The Shared Coin client and server code can be found in blockchain.info's github repository https://github.com/blockchain