Ring Signature
A privacy technique that signs a transaction on behalf of a group, hiding which member actually authorized it.
A ring signature lets someone sign a transaction as one of a group (“ring”) of possible signers, so verifiers can confirm the signature came from someone in the group but can’t tell which one. Applied to payments, it obscures which input actually funded a transaction, breaking the traceability that transparent chains like Bitcoin expose.
Ring signatures are core to Monero, the leading privacy coin, combined with other techniques to hide sender, receiver, and amount. The privacy this provides is genuine and, to some, essential (financial privacy is a legitimate value); to regulators it’s a concern, and privacy coins face exchange delistings in some jurisdictions. Ring signatures illustrate the ongoing tension between crypto’s transparency-by-default and the case for private digital cash.