Glossary
Ring Signature
A signature scheme that proves one member of a group signed a message without revealing which one, hiding the true sender among a set of decoy public keys.
A ring signature lets a signer authorize a message on behalf of a group while keeping their individual identity ambiguous. The verifier learns only that some member of the ring produced the signature, not which one. No coordination or setup among the members is required: the signer simply pulls other parties' public keys from the chain to form the ring.
Monero relies on ring signatures to obscure which output funds a transaction, mixing the real input with decoys so an observer cannot tell who actually spent. Combined with stealth addresses and confidential transactions, they give Monero sender, receiver, and amount privacy by default.