Abstract. An increasingly important design constraint for software running on ubiquitous computing devices is security, particularly against physical methods such as side-channel attack. One well studied methodology for defending against such attacks is the concept of indistinguishable functions which leak no information about program control flow since all execution paths are computationally identical. However, the constructing such functions by hand is laborious and error prone as their complexity increases. We investigate techniques for automating this process and find that effective solutions can be constructed with only minor amounts of computational effort. Keywords. Side-channel Cryptanalysis, Simple Power Analysis, Countermeasures, Indistinguishable Operations.