AuthPaper: Protecting paper-based documents and credentials using Authenticated 2D barcodes

All printed documents/credentials are potentially subject to counterfeiting and forgery. Conventional counterfeiting solutions such as watermarking or printing using special-quality paper are not cost-effective. Certification via authorized chops/stamps is low-cost but only provides a false sense of security/ authenticity. To tackle this problem, we propose AuthPaper: a cost-effective, secure solution for authenticating paper-based documents/credentials using off-the-shelf handheld devices such as smartphones and tablets. The key idea is to extend existing 2D barcodes, e.g. the QR code, to carry a large amount of self-describing, and most importantly, authenticated data of all types containing text, image and other binary ones. By embedding the Authenticated 2D barcode as an integral part of a paper-based document, the authenticity of the document can be readily verified by comparing its content with the corresponding digitally-signed content contained in the Authenticated 2D barcode. No online network-access or real-time communication with the document issuer is required during the document verification process. We have built a prototype using Android smartphones to prove that the proposed system is feasible. As shown by measurements, our prototype can accurately create and decode 2D barcodes carrying different sets of document data including images while the increases in processing time and memory usage are negligible.