Random active shield generation based on modified artificial fish-swarm algorithm

Active shield has already been a primitive sensor of security critical integrated circuits for detecting invasive attacks. Because of the complex topology structure, the active shield based on random Hamiltonian path has a high security level. However, the available generation algorithms of this random path have poor efficiency when shield area is large, restricting its application in integrated circuits. In this paper, a novel generation algorithm of random active shield is proposed using a modified artificial fish-swarm algorithm. By changing the random selection strategy of the generation process, the proposed algorithm makes each selection turn into a successful combination, thus improving the efficiency greatly. Simulations prove that this algorithm is seventeen times faster than the classical Cycle Merging algorithm, while keeping good randomness. Meanwhile, the proposed algorithm is capable of large shield generation. In a 0.18 μm CMOS process with the minimum top-metal width and space of 1.5 μm, the active shield with the area of 3 × 3 mm2 only needs approximately 2 h for generation.