Dictionary · Cybersecurity Fundamentals
Digital Certificate
Cryptography · Intermediate
A signed document that binds an identity to a public key, with a validity period and the issuer's signature. Browsers use one to check that they reached the intended server.
It answers which public key belongs to a name. The issuer's signature lets you trust that binding only if you trust the issuer and the document has not expired or been revoked.
Example: A browser trusts a website's certificate because a known authority signed it and the name matches the site.
Common misconception
- A trusted issuer does not make the website's business honest. It supports the name-to-key binding.