DFSSD: Deep Faults and Shallow State Duality, A Provably Strong Obfuscation Solution for Circuits with Restricted Access to Scan Chain
This addresses hardware security for circuit designers by providing a novel defense against specific attack types, though it appears incremental as it builds on existing logic locking techniques.
The paper tackles the problem of securing sequential and FSM circuits against attacks by introducing DFSSD, a logic locking solution that combines Deep Faults and Shallow State Duality to resist sequential SAT attacks, resulting in a provably strong obfuscation method.
In this paper, we introduce DFSSD, a novel logic locking solution for sequential and FSM circuits with a restricted (locked) access to the scan chain. DFSSD combines two techniques for obfuscation: (1) Deep Faults, and (2) Shallow State Duality. Both techniques are specifically designed to resist against sequential SAT attacks based on bounded model checking. The shallow state duality prevents a sequential SAT attack from taking a shortcut for early termination without running an exhaustive unbounded model checker to assess if the attack could be terminated. The deep fault, on the other hand, provides a designer with a technique for building deep, yet key recoverable faults that could not be discovered by sequential SAT (and bounded model checker based) attacks in a reasonable time.