International Association
for Cryptologic Research

Physically Unclonable Functions (PUFs) are emerging as hardware security primitives. They are mainly used to generate secret keys which are inherently unique for every manufactured sample of a chip. Ring Oscillator (RO) PUFs are among the most widely researched PUFs. In this work, we claim various RO PUF constructions to be vulnerable against manipulation of their public helper data. Partial/full key-recovery is a threat for the following constructions, in chronological order. (1) Temperature-aware cooperative RO PUFs, proposed at HOST 2009. (2) The sequential pairing algorithm, proposed at HOST 2010. (3) Group-based RO PUFs, proposed at DATE 2013. (4) Or more general, all entropy distiller constructions proposed at DAC 2013.