Print signatures for document authentication

We present a novel solution for authenticating printed paper documents by utilizing the inherent non--repeatable randomness existing in the printing process. For a document printed by a laser-printer, we extract the unique features of the non--repeatable print content for each copy. The shape profiles of this content are used as the feature to represent the uniqueness of that particular printed copy. These features along with some important document content is then captured as the print signature. We present theoretical and experimental details on how to register as well as authenticate this print signature. The security analysis of this technique is also presented. We finally provide experimental results to demonstrate the feasibility of the proposed method.