Paper 2000/062

Non-Deforming Digital Watermarks

Gideon Samid

Abstract

TaKE cryptography offers subliminal marking of a digital stream so that any tampering, induces an unacceptable distortion of the primary information. Encrypted audio and video streams are decrypted by one key to the original content (e.g. music), and through another key to the digital watermark (e.g. name of legitimate user). Unlike the prevailing methods which are based on distorting the protected contents, or locking it through a digital signature, TaKE -- Tailored Key Encryption -- preserves the integrity of the original stream, and its digital watermarks are inconspicious. Daniel (tm) is a particular TaKE cryptography which also offers an instant and flexible trade off between security level and speed and convenience level. The described method is fast and proper for both high capacity stream, and secrecy sensitive streams..