Self-encryption for paper document authentication

Sequences of random bits can be extracted from small areas of paper by probing its 3D structure. The same sequence can be obtained with a high probability even after repositioning the sample. Such a random fingerprint can be used for encryption. This property of paper for self-encryption can be used to secure information printed on the document. By combining self-encryption with some classical encryption methods could lead to a significant progress in the fight against counterfeiting because decryption is equivalent to proving originality of the paper document.