인증 문제새로운 문제 발생ㅇ 개인식별정보기반 Identity-based cryptosystem ㅇ 인증서기반 Certification-based cryptosystem ㅇ 자체인증 ... -knowledge proofs Zero-knowledge proofs of identity Blind signatureIdentity-based public-key c ... digital signature , Proxysignature , Group signature , Fail-stop digital signature , Computing with