Abstract
Watermarking is the embedding of data in a medium for ownership, verification, distribution tracking, authentication, copyright protection, and data hiding. It has been well studied for use in digital media such as in audio, digital images and video. In this work, watermarking is extended to the realm of computer-aided design (CAD) for physical design of integrated circuits (IC's) in order to protect and facilitate re-use of intellectual property (IP) blocks (circuitry). As designs become more complex and cycle times shorter, the re-use of IP blocks is becoming more and more important. However, in order to aid in this re-use, improved methods of securing and tracking ownership need to be in place. Watermarking these valuable design blocks, whether custom transistors or standard cells, is shown to be a practical method of securing ownership of the property, even after local perturbations in the design. A method of watermarking circuit elements in both fully-custom analog or digital macrocell designs as well as analog or digital standard cell based designs is presented. This protection scheme thus applies to analog, digital, and mixed signal designs, with the only exception being that of a gate array implemented circuits.