Are Identifier Renaming Methods Secure?

The obfuscation methods are often used to hide sensitive information in software. Especially, an identifier renaming method (IRM) is well used because it is easy to implement. IRM is one of the obfuscation methods, and to change the names of function, and variables into meaningless one. However, if we can restore the identifiers to the original names, IRM is invalidated. One of the serious problems about IRM is that the tolerance against de-obfuscation is not discussed. This paper tries to de-obfuscate IRMed programs. Thereby, this paper evaluates the tolerance and effectiveness of IRM. From the experimental evaluation, the proposed method can restore the 49.71 % of method names to the original verbs. Furthermore, focusing on the meanings of verbs, the proposed method recommends the verbs of similar meanings to the original verbs in 57.01 % of methods.