:speaking_head: Overview # Recently, to prevent cracking, the various protection methods have been proposed. One of the protection methods is the obfuscation method. Obfuscation method changes the program into hard to understand for hiding secret information in the program.
On the other hand, de-obfuscation is an interesting research topic for protecting the software. Since, though vulnerable protection methods are dangerous, measuring the robustness of the method was not discussed.
:speaking_head: Overview # 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.
:speaking_head: Overview # This research topic tries to evaluate the artificialities of the obfuscated programs. We believe that the obfuscation changes the programs into unordinal ones. This topics evaluates the artificialities by tf-idf and perplexities.
:books: Publications # 横井 昂典，玉田 春昭，”使用クラスに基づいたTF-IDFによる難読化の不自然さ評価”，2017年暗号と情報セキュリティシンポジウム予稿集 (SCIS 2017)，3D1-4，January 2017.（沖縄，那覇） 大滝 隆貴，大堂 哲也，玉田 春昭，神崎 雄一郎，門田 暁人，”Javaバイトコード命令のオペコード、オペランドを用いた難読化手法のステルシネス評価”，2014年暗号と情報セキュリティシンポジウム予稿集 (SCIS2014), 2D2-2, January 2014. :mag_right: Related Research Topics # Identifying the applied obfuscator De-obfuscate IRM (identifier renaming method) Evaluating obfuscation method by Kolmogorov complexity Unreadability evaluation of obfuscated programs :handshake: Collaborators # Y. Kanzaki@Kumamoto National College of Technology
:speaking_head: Overview # This paper quantifies the diffuculty of program analysis based on the information theory. The basic idea is to consider that a program ultimately obscated if instructions appear at random; that is (1) all instructions has an equal frequency of appearance, and (2) there is no pattern observed in the instruction sequence. We quantified (1) based on the entropy and (2) based on the Kolmogorov complexity. We evaluated the feasibility of our proposal through a case study.
