Securing physical documents with digital signatures

The majority of important documents continues to be issued as paper-based documents. The security of such documents still relies on increasing the cost of forgery by using special equipment for producing particular features on the document. Cryptographic digital signatures would allow for the production of more secure physical documents without using any special equipment. Hence we elaborate all requirements and a specific realization for securing physical documents based on digital signatures. One crucial question is how to store the digital signature and all auxiliary data on paper. We use JAB Code, a high-capacity matrix code, for this purpose. Our solution notably supports offline verification and satisfies long-term verifiability. A relaxed specification is defined for short-term verification. Finally, we demonstrate our solution for a birth certificate and for a short-dated medical prescription.