Patent attributes
Xerox Docket No. D/A0037Q Document authentication is accomplished by acquiring document image data, generating a set of features of the document, and generating an assist channel that includes information on how to generate the set of features. The set of features and the assist channel are digitally signed and then append to the document. Document verification is accomplished by acquiring document image data and verifying the signature. If the signature is valid, a set of features of the document is generated using information contained in the assist channel appended to the document. The generated set of features is then compared to the set of features appended on the document. If the sets do not match, the document is determined to have been altered sometimes after the assist channel was appended to the document, i.e., the document is not genuine. Otherwise, the document can be considered to be genuine.