Definition
A ring signature is a cryptographic method that allows one person in a group to sign a message in a way that proves someone in the group signed it, without revealing exactly who. It uses a collection of public keys from multiple users to form a “ring,” and the final signature mathematically depends on all of them. Because of this structure, outside observers can verify that the signer is a valid member of the group, but cannot link the signature to any specific individual. In cryptocurrency systems, ring signatures are used to make it difficult to trace which address actually authorized a transaction.
In Simple Terms
A ring signature is like a digital signature made on behalf of a small crowd instead of a single person. Everyone in the crowd could have been the signer, and the math proves that at least one of them really did sign, but there is no clear way to tell which one. This gives the actual signer a layer of anonymity while still keeping the signature valid and verifiable. In coins that focus on privacy, ring signatures help hide the true source of funds while maintaining trust that the transaction is legitimate.