IDENTIFYING MATERIAL

摘要

A method of identifying material comprises the step of inserting an identifying code into a signal as a watermark, and deriving a signature from the material. The code and signature are stored in a database. The watermarked signal may be distributed and/or transmitted through a network. The signal may be processed in the network. A monitor derives from the received signal, the signature and the code. They are compared with the stored signature and code to check the provenance of the material.