Deterministic, Efficient Variation of Circuit Components to Improve Resistance to Reverse Engineering

This research proposes two alternative methods for generating semantically equivalent circuit variants which leave the circuit\u27s internal structure pseudo-randomly determined. Component fusion deterministically selects subcircuits using a component identification algorithm and replaces them using a deterministic algorithm that generates canonical logic forms. Component encryption seeks to alter the semantics of individual circuit components using an encoding function, but preserves the overall circuit semantics by decoding signal values later in the circuit. Experiments were conducted to examine the performance of component fusion and component encryption against representative trials of subcircuit selection-and-replacement and Boundary Blurring, two previously defined methods for circuit obfuscation. Overall, results support the conclusion that both component fusion and component encryption generate more secure variants than previous methods and that these variants are more efficient in terms of required circuit delay and the power and area required for their implementation

Candidate Subcircuits for Functional Module Identification in Logic Circuits

Recovering functional information from existing hardware is a difficult problem in design automation. However, it is an important focus for designers attempting to redesign for expanded functionality or superior performance. Often, the only reliable information available about a piece of digital hardware is the hardware itself. Documentation, even if it is available, may be outdated or incorrect. Existing procedures are able to recover the transistor-level netlist, or a gate-level netlist from an existing implementation. The next step in this process is the gate-level to module-level transformation, the focus of this paper. We have designed a technique to enumerate all of the potential modules within a gate-level netlist so that their functional equivalence to known modules may be evaluated