Certification Authorities (CA)

Organizations that manage public key certificates.

Define policies and mechanisms for.

• Issuing certificates.

• Revoking certificates.

• Distributing certificates.

• Issuing and distributing the corresponding private keys.

Manage certificate revocation lists.

• Lists of revoked certificates.

CA types

Intermediate CAs.

• CAs certified by other CAs.

Root CAs.

• CAs for which one has a trusted public key.

• Trust anchor.

• Usually implemented by self-certified certificates.

  • Issuer = Subject.

  • Self-certification is not a reason for trusting!

• Manual distribution.

  • Tools’ repositories (Firefox, Thunderbird, etc.).

  • Operating systems’ repositories.