A Dynamic Soft-Decision Fuzzy Extractor for a CMOS Image Sensor PUF
Shunsuke Okura, Ryota Ishiki, Masayoshi Shirahata, Takaya Kubota, Mitsuru Shiozaki, Kenichiro Ishikawa, Isao Takayanagi, Takeshi Fujino · 2018
As information interfaces in the Internet of Things (IoT) age, sensor devices require high security. Thus, a CMOS image sensor (CIS) physically unclonable function (PUF) was proposed for authenticating imaging devices. However, the PUF response must contain no bit error for cryptographic purposes. Conventionally, a soft-decision fuzzy extractor was developed to regenerate an encryption key repeatedly in which error is corrected by using helper data. The helper data is reliability information of each PUF response bit and requires large circuit overhead. For the CIS PUF, this paper proposes a novel dynamic soft-decision fuzzy extractor that utilizes a Gaussian error function to dynamically derive the reliability of each PUF response bit. Measurement and simulation results demonstrate that the proposed fuzzy extractor has high error correction capability with small circuit overhead.