Confirming ones identity on a paper document, with means of classical non-electronic ways of performing signatures, is becoming less and less suitable due to the rapid development of computer technology. Advanced professional software and hardware equipment has in the past few years become rapidly accessible to most computer users, in which the open source community played an important role. Data processing and processing of digital imagery has become an easy task, as knowledge on how to perform the tasks is available, practically everywhere. Creating forged documents is becoming a trivial task, verifying its authenticity but hard and costly. Using an electronic document with an electronic signature can accomplish the opposite — difficult forgery and trivial verification of authenticity.
Electronically signed documents improve security when performing business electronically. It enables carrying out business on a distance without the need of a persona to move physically. It is likely that electronic signatures will replace the classical handwritten signatures. Despite all the advantages of an electronic signature, it does have one major flaw in the current implementations. People are used to and like working with paper documents or with software which imitates a paper document. An electronically signed document that has been printed loses its signature, since the signature itself is saved in the meta-data.
An electronic cryptographic signature retaining authenticity after being printed out would have the benefit to be used more intuitively, in the same way as a classical paper document. A public administration office could send such electronically written document to a citizen's e-mail. A printed out, as well as afterwards photocopied version of such document would retain authenticity. It could be used the same way as a classical document signed with classical means. For such a document, the distinction between a classical and electronic document would no longer be necessary because such a document would be the equivalent.
For proof of concept I have programmed a smartphone application called Digital Inkan. The APP has a simple text editor built in, where the author of the document can write down a statement. This statement can then be signed using the author's private key. Both electronic document and his signature are then stored in the form of QR code directly on a canvas in front of the eyes of the author.