Steganography

Innovative new techniques are being developed to address security- or management-driven concerns relating to dissemination and use of digitally-encoded information. For example, methods have been developed that can encode digitized information with attributes that cannot be disassociated from the file that contains that information. This field of technology has been termed "steganography" and been conceptually referred to as "digital fingerprinting" or "digital watermarking."

In essence, using steganographic techniques, a party can embed hidden messages in [digitized]] visual or audio data. The embedded information does not degrade or otherwise interfere with the audio or visual quality of the work. Instead, the embedded information can only be detected if specifically sought out.

More advanced steganographic techniques based on statistical or entropically-directed encoding are proving to be difficult to defeat. For example, one system modulates a known noise signal with the information to be embedded and adds the "scaled" signal to the original data. Once encoded in this fashion, the steganographically encoded identification data is distributed throughout the work as subliminal noise and, like noise, cannot be fully eliminated from the work. Thus, one can ensure detection of an embedded message even after substantial corruption of the data, such as might occur through compression/decompression, encoding, alteration or excerpting of the original data. By providing a means to indelibly tag a work with specific information, steganography is likely to play a complementary role to encryption as well as authentication techniques based on digital signatures.