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Intellectual property (IP) piracy and electronic counterfeiting have emerged as critical threats to the semiconductor industry in the current horizontal business model where the supply chain usually involves a large number of vendors. Hence, techniques that can protect integrated circuit (IC) against reverse engineering are demanded, especially for security-critical tasks. Hardware obfuscation is a broad category of techniques that could create ambiguity to the adversary by hiding the actual information from illegitimate users. This paper presents a novel hardware obfuscation design through reconfigurable finite field arithmetic units, which can be employed in various error correction and cryptographic algorithms. The effectiveness and efficiency of the proposed methods are verified by an obfuscated reformulated inversion-less Berlekamp-Massey (RiBM) Reed-Solomon decoder. Our experimental results show the hardware implementation of RiBM based Reed-Solomon decoder built using reconfigurable field multiplier designs. The proposed design provides only very low overhead.

To protect intellectual property, hardware obfuscation is necessary to conceal the implemented function. Besides logic-level approaches, hardware obfuscation can be done through algorithmic modifications. Prior algorithmic obfuscations address signal processing systems and those with variable data flow. This paper focuses on the obfuscation of systems based on finite field arithmetic, which are broadly adopted in digital communications. Netlists of hardware units with different field constructions are first analyzed to evaluate possible attacks. Taking into account the specifics of the computations in the Advanced Encryption Standard (AES) algorithm, optimized schemes are proposed to efficiently introduce obfuscation keys utilizing the variation of finite field construction. For an example pipelined fully-unrolled AES encryptor, the proposed scheme leads to 480 bits of obfuscation key with 3% area overhead without sacrificing the throughput. The proposed obfuscation method can be also extended to other algorithms involving finite field arithmetic.