One of the challenges created by today's proliferation of intellectual property (IP) is keeping track of it in the field. If I create a core and sell it to a third party, how do I verify that it is being used in accordance with the licensing contract? I could put an ID on my IP prior to selling it—but traditional ID approaches such as EPROM, flash, or laser trimming require extra processing steps and masks, as well as special handling and programming. Reliability also tends to be a large issue for most of these conventional methods.
SiidTech, Beaverton, Ore., has developed an alternative, patent-pending technology nicknamed "silicon fingerprinting." Similar to a human fingerprint, this method is intrinsic to the chip. Much like a Social Security number, it also acts as a source for complete identification. It works by leveraging the random phenomenon inherent in the chip-manufacturing process to create a unique ID that can't forged or altered, uses standard CMOS processing.
With SiidTech's approach, a circuit is embedded into each chip as it is produced on the fab line. The circuit is nothing more than a digital bit pattern of ones and zeros. The number of bits in the ID depends on how many chips are in the population. During production, each bit sequence acquires a random pattern. The result is a group of chips that have essentially inherited an ID as part of the manufacturing process. Each chip ends up with a sequence that is completely unique.
Once the chips have been given an ID, they can be probed. The corresponding IDs then can be read and stored in a database with pertinent information for later use. This would typically happen as the chips come off the fab line. The ID takes up no more space than the size of a pad, if even that. And, it may use anywhere from zero to four extra pins.
In the field, the chip ID can be easily read electronically using a JTAG bus. When the ID isn't being scanned, it doesn't draw any power. During the scan, it may draw as little as a microamp-type current.
SiidTech's proposed silicon fingerprinting technology claims to offer a number of highly advantageous capabilities that differentiate it from other currently available options. Ultimately, though, the concept needs to be proven in the real world. Toward that end, the company has already built a prototype with HP's 0.35-µm process technology, which was able to produce between 7000 and 8000 IDs.
For more information about silicon fingerprinting, contact SiidTech's vice president of marketing, Steve Sapiro, at [email protected].