Password Manager Combining Hashing Functions and Ternary PUFs

Hashing functions protect passwords against various hacking techniques because message digests can replace the passwords when stored in the network for future authentication. However, the message digests remain exposed to password guessing attacks, most hashing functions are known, and public. The objective of the protocols presented in this paper is to offer additional lines of defense using physical unclonable functions to convert the message digests into challenge-response pairs. The use of ternary physical unclonable functions reduces false rejection rates, and lowers the latencies during the processing of the authentications. Without having access to the PUFs, the look up tables storing challenge-response pairs are more difficult to attack than those storing message digests: they are unclonable, contain high levels of randomness, and quasi unique. The modeling efforts, and algorithms developed in this paper to validate the schemes, use commercially available components, and SRAM based ternary PUFs.