http://www.datasection.co.jp/news/2014/04/20140417.html
http://s.news.mynavi.jp/news/2014/04/17/557/
http://mw.nikkei.com/sp/#!/article/DGXNZO65605330Q4A120C1TJM000/
http://www.slideshare.net/tomowatanabe/os-30126094
http://m.jp.techcrunch.com/2013/12/21/20131220nsa-reportedly-paid-a-security-firm-millions-to-ship-deliberately-flawed-encryption-technology/