* Container image signing (e.g., withcosign, Notary v2) uses asymmetric cryptography.
* Verification process:
* Retrieve theimage's digital signature.
* Validate the signature with thepublic keyof the signer.
* Exact extract (Sigstore Cosign Docs):
* "Verification of an image requires the signature and the signer's public key. The signature proves authenticity and integrity."
* Why others are wrong:
* A & B: The private key is only used by the signer, never shared.
* C: The hash alone cannot prove authenticity without the digital signature.
References:
Sigstore Cosign Docs: https://docs.sigstore.dev/cosign/overview