Binary synthesis can be used to reduce the attack surface of high-risk computing applications. In this presentation we discuss binary synthesis and some of its applications within the domain of computer security. We describe techniques that we have devised which increase the security and determinism of synthesized binaries, and discuss countermeasures targeted for deployment against a highly motivated adversary. We present automated behavioral divergence of synthesized binaries as one such countermeasure, and describe our ongoing investigation of this area.