Takuho MITSUNAGA is a Project Associate Professor at the Graduate School of Interfaculty Initiative in Information Studies, The University of Tokyo. He is also a Research Fellow at Information-technology Promotion Agency in Japan. After completing his degree at Graduate School of Informatics, Kyoto University, Mr. Mitsunaga worked at the front line of incident handling and penetration testing at a security vendor. In FY 2010, he led an R&D project of the Ministry of Trade, Economy and Industry (METI) for encryption data sharing system for cloud with an efficient key managing function. He has been a member of Watch and Warning Group of JPCERT/CC since April 2011, where he is engages in cyber attack analysis including APT cases. He has also contributed in some cyber security related books as coauthor or editorial supervisor including " Information Security White Paper 2013".