Certification Practice Statement

A Certification Practice Statement (CPS) 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 certificates.^[1]

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.^[2]

Certificate authorities

Main article: Certificate authority

In a certificate authority, the CPS should derive from the organization's certificate policy and may be referenced in issued certificates.^[3]

Web of trust

Main article: 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

Main article: Digital signature

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.^[4]