Multi-pair Active Shielding for Security IC Protection

Active shielding techniques are effective methods to prevent attacks of probing or FIB. Many research groups proposed methods for automatically metallic shield generation but few considered the multi-pair and shield aligning requirements. In this paper, the active shielding problem is redefined considering both requirements and a novel two-phase method is proposed to solve it. A coverage-oriented initial routing algorithm is performed to generate initial random paths for each routing-pair and an ILP-based tile routing algorithm is presented to generate complex shield lines. Experimental results show that the proposed method is very effective and the generated shield can satisfy all design principles of connectivity, full-coverage, randomness, and complexity. When compared to traditional methods, it can solve all test cases while improving routability by 67.7% and reducing solving time by 99.1%.