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Certificate Authority (CA)

Security

TLS (Transport Layer Security) Certificate Pinning HTTPS Man‑in‑the‑Middle (MITM) Attack

PKI entity that signs and validates X.509 certificates.

Definition

CAs are part of public key infrastructure (PKI) and issue X.509 certificates binding domain identities to public keys, enabling TLS authentication.

In plain English PKI entity that signs and validates X.509 certificates.

Why this matters

Why it matters: CA trust anchors affect confidentiality; CA compromise or mis-issuance can enable MITM attacks.

Example

Example: Browser trust store contains CA roots used to validate server certificates.