RE - TRUST Deliverable D 4 . 3 – Analysis of the Reverse Engineering Complexity 2 T ABLE OF

Source code obfuscation is a protection mechanism widely used to limit the possibility of malicious reverse engineering or attack activities on a software system. Although several code obfuscation techniques and tools are available, little knowledge is available about the capability of obfuscation to reduce attackers' efficiency, and the contexts in which such an efficiency may vary. This document reports the outcome of two controlled experiments meant to measure the ability of subjects to understand and modify decompiled, obfuscated Java code, compared to decompiled, clear code. Results quantify to what extent code obfuscation is able to make attacks more difficult to be performed, and reveal that obfuscation can mitigate the effect of factors that can alter the likelihood of a successful attack, such as the attackers' skill and experience, or the intrinsic characteristics of the system under attack.