X.509 facts for kids
In cryptography, X.509 is a common "PKI" (public key infrastructure) used to manage digital certificates and public-key encryption and a key part of the Transport Layer Security protocol used to secure web and email communication. X.509 specifies ways in which public key certificates, certificate revocation lists, attribute certificates, and a certification path validation algorithms are formatted.
X.509 Facts for Kids. Kiddle Encyclopedia.