ANSI/X9 X9.55-1997

Specifies extensions to the definitions of public-key certificates and certificate revocation lists in Public Key Cryptography for the Financial Services Industry: Certificate Management, BSR X9.57. These extensions are in the following areas: the keys involved, including key identifiers for subject and issuer keys, indicators of intended or restricted key usage, and indicators of certificate policy; name forms for a certificate subject, a certificate issuer, or a CRL issuer, and additional attribute information about a certificate subject; included in CA-certificates, i.e., certificates for CAs issued by other CAs, to facilitate the automated processing of certification paths when multiple certificate policies are involved, e.g., when policies vary for different applications in an environment or when interoperation with external environments occurs; and time at which the condition causing the revocation occurred; revocation information from one CA to be partitioned into separate CRLs to facilitate control of CRL sizes, and CRL extensions to support the use of partial CRLs indicating only changes since an earlier CRL issue.