In cryptography

Cryptography

Cryptography is the practice and study of techniques for secure communication in the presence of third parties...

, a certificate authority, or certification authority, (CA) is an entity that issues digital certificate

Public key certificate

In cryptography, a public key certificate is an electronic document which uses a digital signature to bind a public key with an identity — information such as the name of a person or an organization, their address, and so forth...

s. The digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) to rely upon signatures or assertions made by the private key that corresponds to the public key that is certified. In this model of trust relationships, a CA is a trusted third party

Trusted third party

In cryptography, a trusted third party is an entity which facilitates interactions between two parties who both trust the third party; The Third Party reviews all critical transaction communications between the parties, based on the ease of creating fraudulent digital content. In TTP models, the...

 that is trusted by both the subject (owner) of the certificate and the party relying upon the certificate.