Using Intermittent Chaotic Clocks to Secure Cryptographic Chips

This letter proposes using intermittent chaotic clocks, generated from chaotic maps, to drive cryptographic chips running the advanced encryption standard as a countermeasure against correlation power analysis (CPA) attacks. Five different chaotic maps, namely, the logistic map, the Bernoulli shift map, the Henon map, the tent map, and the Ikeda map, are used in this letter to generate chaotic clocks. The performance of these chaotic clocks is evaluated in terms of timing overhead and the resilience of the driven chip against CPA attacks. All proposed chaotic clocking schemes successfully protect the driven chip against attacks, with the clocks produced by the optimized Ikeda, Henon, and logistic maps achieving the lowest-timing overhead. These optimized maps, due to their intermittent chaotic behavior, exhibit lower-timing overhead compared to previous work. Notably, the chaotic clock generated by the optimized Ikeda map approaches the theoretical limit of timing overhead, i.e., half the execution time of a reference periodic clock.