# Prevention of Additional Untrusted Signatures

**Objective**

Stop anyone from quietly adding an unauthorized or untrusted signature to a document that was already signed by the system.

**Guidelines**

A document signed through the PKI system must be protected so that extra, untrusted signatures cannot be added without detection.

**Example:** Someone should not be able to take a document signed by your system, add their own signature using an untrusted certificate, and have it appear legitimate.