A standardised digital certificate format that binds a public key to an entity identity, together with validity period and usage constraints, and is signed by a certificate authority within a public key infrastructure so that relying parties can cryptographically verify its authenticity.
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Content
- An X.509 certificate is a structured data record that associates a public key with a subject identity, together with metadata such as validity period and intended usage. It is signed by a trusted certificate authority so that relying parties can verify its authenticity.
- The format is foundational to public key infrastructure and is used in Transport Layer Security, secure email and code signing. Certificate chains link an end-entity certificate to a trusted root through one or more intermediate authorities.