Several new applications have sprung up in the 1990’s. Whether these applications prove economically viable remains to be seen, but we can offer some educated guesses based on how well the current state of the art satisfies the applications’ requirements. We discuss, in turn, the applications of transaction tracking (also known as fingerprinting), proof of ownership, copy control, legacy system enhancement, and a range of applications we refer to broadly as database linking.

On the other hand, smaller-scale transaction tracking applications, in which collusion attacks are unlikely, can probably be implemented with a very high degree of security. For example, if a Hollywood studio wishes to distribute movie dailies to a few key personnel, it is extremely unlikely that even two executives would collude in leaking these movie clips to the press. By using the original clip during the detection process (informed detection), a studio could design a watermark that is very difficult to remove.

The more serious problem in implementing a watermarking copy-control system is the political problem of persuading manufacturers to include watermark detectors in their recording devices. These detectors add cost yet do not necessarily add any value to the equipment. In fact, they reduce the value, since many consumers would like to be able to make illegal recordings. Thus, equipment manufacturers must be forced to include detectors, by a combination of laws and contractual obligations. The political wrangling that results, together with conflicts over patent rights, are probably greater impediments to the deployment of these systems than any technical problems.