Secret-key certificates (continued)

A new construction is described for designing secret-key certificate schemes based on signature schemes other than of the Fiat-Shamir type. Also described are practical secret-key certificate issuing protocols that enable the Certification Authority to certify public keys, without being able to compromise the confidentiality of the corresponding secret keys. Furthermore the design of secure showing protocols is discussed, exemplified by secret-key certificate schemes based on Fiat-Shamir type signature schemes.