Authorizing method for digital signatures in portable document format (PDF) documents stores authorizing data in a PDF document for checking signatures

摘要

Entitlements to digital signatures are stored for each signature to be attached directly in a portable document format (PDF) document to be signed. There are permissible ranges of values for attributes for a digital signature. Authorization data is used for checking signatures contained. An independent claim is also included for a system for verifying signature entitlement for digital signatures in portable document format (PDF) documents.