Bytecoin

Bytecoin is the first cryptocurrency created with CryptoNote technology. Bytecoin allows users to make absolutely anonymous money transfers through the CryptoNote algorithm. CryptoNote uses CryptoNote ring signatures to provide anonymous transactions and allows you to sign a message on behalf of a group. The signature only proves the message was created by someone from the group, but all the possible signers are indistinguishable from each other.