Which formal statement asserts ownership of a public encryption key?

• A. Certificate
• B. Credential
• C. Token
• D. License

Answer: (A)

A digital certificate is the formal statement that binds a public key to the identity of its owner and is issued by a trusted authority. It carries the owner’s identity, the public key, and metadata like validity period, all signed by a certificate authority. When you receive a certificate, you can verify the CA’s signature to trust that the public key really belongs to the claimed owner, since the owner controls the corresponding private key. This binding enables secure operations like TLS, where the authenticity of the public key is essential for establishing trust.

A credential is a broad term for proof of identity or authorization but doesn’t specifically bind a public key to its owner. A token is a separate form of proof used for authentication or access, not primarily about binding a key to an owner. A license is permission to use software or services, not a statement about key ownership.