How does e-signature work on grading decisions?

Every clinician approval is cryptographically signed using SHA-256 hashing of the record state plus the signer identity plus the timestamp. Signatures are tamper-proof: any change to the underlying record invalidates the signature and the prior state remains recoverable. The signature is bound to the user's authenticated session, satisfies 21 CFR Part 11 electronic signature requirements, and is referenceable in regulatory submissions.