Watermarking strategies for RNS-based system intellectual property protection

This paper present a new procedure for intellectual property protection (IPP) of circuits based on the residue number system (RNS). The aim is to protect the author rights of reusable IP cores by means of an electronic digital signature that uniquely identifies both the original design and the design recipient. The signature embedding stores the digital signature in non-used positions of look-up tables of RNS-based designs. This embedding does not increase the area of the system. A procedure for signature extraction is also included, so it is possible to detect the ownership right without interfering the normal operation of the system. This signature extraction requires some extra hardware, basically additional logic and some multiplexers. As an example, a 160-bit signature is introduced into a FIR filter. The presented IPP design examples are implemented over FPL devices and cell-based ASICs with negligible performance penalties.