MOVES Seminar 6 July 2010, 10:30

 

Carsten Fuhs

 

 

 Synthesizing Shortest Linear Straight-Line Programs over GF(2) using SAT

Abstract:

 Non-trivial linear straight-line programs over the Galois field of
two elements occur frequently in applications such as encryption or
high-performance computing. Finding the shortest linear straight-line
program for a given set of linear forms is known to be MaxSNP-complete,
i.e., there is no epsilon-approximation for the problem unless P = NP.

We present a non-approximative approach for finding the shortest linear
straight-line program. In other words, we show how to search for a
circuit of XOR gates with the minimal number of such gates. The
approach is based on a reduction of the associated decision problem
("Is there a program of length k?") to satisfiability of propositional
logic. Using modern SAT solvers, optimal solutions to interesting
problem instances can be obtained.