The subject matter includes systems, engines, methods, and schemata for embedding spread-spectrum fingerprints in multimedia content: a first fingerprint to identify a recipient of the multimedia content and a second fingerprint at a location in the first fingerprint that represents a subset of a much...http://www.google.com.au/patents/US7562228?utm_source=gb-gplus-sharePatent US7562228 - Forensic for fingerprint detection in multimedia
