A facsimile system and method provides authentication of transmitted image information, which authentication may be in the form of a signature page. An authentication device computes authentication information at a sending device, a receiving device, both, or at a remote location during transmission. The signature page may also be transmitted with the document. The sending and receiving devices may each generate signature pages or acknowledgement of receipt in response to receiving a signature page. The authentication information may be encrypted with a public/private key pair. The authentication information may be in the form of a checksum, and may be prepared based on separate regions of the document. A previously generated signature page is compared to a newly generated signature page to verify the document content or authenticity. Document authentication signatures may include machine-readable symbols to represent the authentication information.