Visible to the public JANUS: Boosting Logic Obfuscation Scope Through Reconfigurable FSM Synthesis

TitleJANUS: Boosting Logic Obfuscation Scope Through Reconfigurable FSM Synthesis
Publication TypeConference Paper
Year of Publication2021
AuthorsLi, Leon, Ni, Shuyi, Orailoglu, Alex
Conference Name2021 IEEE International Symposium on Hardware Oriented Security and Trust (HOST)
Keywordsboosting, Hardware, hardware security, Heuristic algorithms, Human Behavior, logic locking, logic obfuscation, Partitioning algorithms, pattern locks, pubcrawl, resilience, Resiliency, Scalability, security, Supply chains, Switches, Tamper-proof Memory
AbstractLogic obfuscation has been proposed as a counter-measure against supply chain threats such as overproduction and IP piracy. However, the functional corruption it offers can be exploited by oracle-guided pruning attacks to recover the obfuscation key, forcing existing logic obfuscation methods to trivialize their output corruption which in turn leads to a diminished protection scope. In this paper, we address this quandary through an FSM obfuscation methodology that delivers obfuscation scope not only through external secrets but more importantly through inherent state transition patterns. We leverage a minimum-cut graph partitioning algorithm to divide the FSM diagram and implement the resulting partitions with distinct FF configurations, enabled by a novel synthesis methodology supporting reconfigurable FFs. The obfuscated FSM can be activated by invoking key values to dynamically switch the FF configuration at a small number of inter-partition transitions. Yet, the overall obfuscation scope comprises far more intra-partition transitions which are driven solely by the inherent transition sequences and thus reveal no key trace. We validate the security of the proposed obfuscation method against numerous functional and structural attacks. Experimental results confirm its delivery of extensive obfuscation scope at marginal overheads.
DOI10.1109/HOST49136.2021.9702288
Citation Keyli_janus_2021