Secure and resilient data printed on paper

Transmission and printing of sensitive information requires both data security, and protection against random and burst errors. This paper describes a technique that achieves two objectives: secure and reliable transmission of information; and integrity of the original information printed on paper. Information printed on paper is prone to burst and random errors. Resilience of the information to such errors is obtained by introducing redundancy into the original data using forward error correcting codes. We have selected a concatenation of a Reed-Solomon (RS) code, interleaved with a self-orthogonal majority decodable convolutional code. To measure the performance of the concatenated code, the bit error rate against signal to noise ratio of the code is compared with codes of equivalent rate (e.g., RS code alone) and with the unencoded data. Security of the printed data can be achieved through encryption. We have selected a probabilistic encryption scheme of messages to achieve an increased security against reverse engineering of the printed pattern. A new document signature extraction scheme based on fractal signal processing is described. Such a signature is then included with the document in the security pattern.