Secure storage of cryptographic keys is a popular application for responses generated from physical unclonable functions (PUFs). It is, however, required to correct these noisy PUF responses in order to derive the same key under all environmental conditions. This is enabled by mapping the random response pattern of the PUF to codewords of error correcting codes using so called helper data, and by proper error correction mechanisms. This chapter maps the process of key storage with PUFs to the information theoretic model of key agreement from a compound source and shows theoretical bounds. It introduces a unified algebraic description of helper data generation schemes that is able to represent most state-of-the-art approaches. This is used together with the theoretic bounds to analyze the existing schemes. The focus here is secrecy leakage through the helper data. The new representation will allow the analysis of future schemes in an early design phase.      «

Secure storage of cryptographic keys is a popular application for responses generated from physical unclonable functions (PUFs). It is, however, required to correct these noisy PUF responses in order to derive the same key under all environmental conditions. This is enabled by mapping the random response pattern of the PUF to codewords of error correcting codes using so called helper data, and by proper error correction mechanisms. This chapter maps the process of key storage with PUFs to the in...     »