Digital signatures with familiar appearance for e-government documents: authentic PDF

Most e-government applications have to find a solution for simple, reliable, secure and authentic signing of official documents. Citizens need a simple way to verify the authenticity and integrity of an official document. Currently XML documents allow representing such documents. However, the XML format does not guarantee a definite visual presentation of the document (presentation problem). In this paper we describe a solution approach -so-called authentic PDF - using PDF technology that fulfills the following key requirements: 1) A visual presentation that resembles the traditional style of an official document; 2) A visual representation of the signature value that does not change the document authenticity; 3) The option for the holder of an official document to restore the electronic version of the authentic official document from the visual representation of the document (e.g. printout); 4) The filtering of dynamic content. We implemented and evaluated different approaches in a feasibility study using a typical e-government document set. The results of the study indicate that PDF is suitable to meet specific legal requirements on a signature solution in combination with a smartcard; the method has proven to be reliable and support a sufficient level of security.