Built-in hardware pseudo-random test module for physical unclonable functions

Abstract

PUFs, that self-generate random numbers, are used in identification or authen- tication applications for two reasons: cost and security. Since the randomness of PUFs in individual chips may differ, PUFs in some chips may generate somewhat less than random values. Defects during manufacturing may also affect the randomness of PUFs. In either case, confidential information based on PUF's could be vulnerable to security threats. Thus, it is nec- essary to identify both failing chips during manufacturing and PUFs which are not sufficiently random. To test the randomness of PUFs in a chip, we have designed a dedicated random test module optimized for hardware implementation. Finally, by implementing the module in real PUFs, we verified its validity.