High-Rate Error Correction Schemes for SRAM-PUFs based on Polar Codes.

Physical unclonable functions (PUFs) can be used to generate cryptographic keys by making use of the intrinsic randomness resulting from manufacturing variations. Error correction codes (ECCs) help to make SRAM-PUFs, which are always effected by noise and environmental changes, suitable for security applications. In this paper, we propose practical error correction schemes for PUF-based secret generation that are based on polar codes. The proposed scheme could generate a 128-bit key using 1024 PUF bits and $896$ helper data bits and achieve a failure probability of 10^{-9} or lower for a practical SRAM-PUFs setting with cross-over probability of 15%. The method is based on successive cancellation in combination with list decoding and hash-based checking, making use of the hash that is already available at the decoder. In addition, an adaptive list decoder for polar codes is investigated. This decoder increases the list size only if needed.