Watermarking-based copyright protection of sequential functions

Watermarking is one of several techniques available toda to deter copyright infringement in electronic systems. The technique consists of implanting i ndelible stamps in the circuit's inner structure, while not disrupting its functionality nor degrading its performance significantly, In this paper, a novel method is proposed for the creation of watermarks in regular sequent ial functions. This is an important class of functions, as it is the basis of mast digital controllers. Algorithms are proposed for implanting robust watermarks to minimize the ol overhead and, ultimately to reduce the impact on performance. Detection methods have been discussed in the presence of i nfringement attacks. The resilience of the method in several tampering regi mes has been estimated, Examples illustrate the suitability of the approach .