Practical implementations of program obfuscators for point functions
Giovanni Di Crescenzo, Lisa Bahler, Brian Coan, Yuriy Polyakov, Kurt R. Rohloff, David Bruce Cousins · 2016
Point function obfuscators have recently been shown to be the first examples of program obfuscators provable under hardness assumptions commonly used in cryptography. This is remarkable, in light of early results in this area, showing impossibility of a single obfuscation solution for all programs. Point functions can be seen as functions that return 1 if the input value is equal to a secret value stored in the program, and 0 otherwise. In this paper, we select representative point function obfuscators from the literature, state their theoretical guarantees, and report on their (slightly) optimized implementations. We show that implementations of point function obfuscators, satisfying different obfuscation notions, can be used with practical performance guarantees. Notable implementation results due to our design and coding optimizations are: (a) very fast obfuscators based on group theory, and (b) obfuscators based on lattice theory with running time <; 8s, using inexpensive computing resources.