Instruction Set Limitation in Support of Software Diversity

This paper proposes a novel technique, called instruction set limitation, to strengthen the resilience of software diversification against collusion attacks. Such attacks require a tool to match corresponding program fragments in different, diversified program versions. The proposed technique limits the types of instructions occurring in a program to the most frequently occurring types, by replacing the infrequently used types as much as possible by more frequently used ones. As such, this technique, when combined with diversification techniques, reduces the number of easily matched code fragments. The proposed technique is evaluated against a powerful diversification tool for Intel’s x86 and an optimized matching process on a number of SPEC 2006 benchmarks.