WebSocket proxy system for mobile devices. - Hirotaka Nakajima; Masao Isshiki; Yoshiyasu Takefuji (GCCE, 2013)

Out-of-band authentication protocol for digital signage and smartphone interaction. - Hirotaka Nakajima; Shigeya Suzuki; Tetsuro Tokunaga; Kiyoshi Tanaka; Yasuhiko Miyazaki; Koichi Maruyama; Osamu Nakamura (GCCE, 2016)

Securing Cryptocurrency Exchange: Building up Standard from Huge Failures. - Yuji Suga; Masaki Shimaoka; Masashi Sato; Hirotaka Nakajima (Financial Cryptography Workshops, 2020)