Physical unclonable function generation and management

摘要

Methods, systems and devices related to authentication of chips using physical physical unclonable functions (PUFs) are disclosed. In preferred systems, differentials of PUFs are employed to minimize sensitivity to temperature variations as well as other factors that affect the reliability of PUF states. In particular, a PUF system can include PUF elements arranged in series and in parallel with respect to each other to facilitate the measurement of the differentials and generation of a resulting bit sequence for purposes of authenticating the chip. Other embodiments are directed to determining and filtering reliable and unreliable states that can be employed to authenticate a chip.

主权项

1. A circuit authentication system comprising:
a plurality of physical unclonable function (PUF) elements including a first subset of PUF elements that are arranged in series and a second subset of PUF elements that are arranged in series, wherein the first subset of PUF elements is arranged in parallel with respect to the second subset of PUF elements; a measurement unit configured to measure at least one differential of states between said first subset of PUF elements and said second subset of PUF elements at respective intermediate connection points between two serially connected PUF elements in the first subset and between two serially connected PUF elements in the second subset, said at least one differential of states forming a basis of at least part of a bit sequence of an authentication signature for said circuit; and a filter configured to filter unreliable states determined by the measurement unit by replacing said unreliable states with predetermined bits, wherein the first subset and the second subset exclude current mirrors.