Certification Practice Statement


A Certification Practice Statement is a document from a certificate authority or a member of a web of trust which describes their practice for issuing and managing public [key certificate]s.
Some elements of a CPS include documenting practices of:
  • issuance
  • publication
  • archiving
  • revocation
  • renewal
By detailing the practice of issuance, revocation and renewal, a CPS aids entities in judging the relative reliability of a given certificate authority.

Certificate authorities

In a certificate authority, the CPS should derive from the organization's certificate policy and may be referenced in issued certificates.

Web of trust

Because individuals act as certifiers in a web of trust, individual CPS documents are sometimes used. For example, in a PGP WoT, the CPS might state that the certifying entity checked two forms of legal government ID before signing the person's public key.

Digital signatures

When verifying digital signatures, it's necessary to review the CPS so as to determine the meaning of the issuance of the certificate by the certifying entity.