Security of Digital Signature Schemes in Weakened Random Oracle Models. - Akira Numayama; Toshiyuki Isshiki; Keisuke Tanaka (Public Key Cryptography, 2008)

Security on Hybrid Encryption with the Tag-KEM/DEM Framework. - Toshihide Matsuda; Ryo Nishimaki; Akira Numayama; Keisuke Tanaka (ACISP, 2009)

On the Weak Ideal Compression Functions. - Akira Numayama; Keisuke Tanaka (ACISP, 2009)

Security of Encryption Schemes in Weakened Random Oracle Models. - Akinori Kawachi; Akira Numayama; Keisuke Tanaka; Keita Xagawa (IACR Cryptol. ePrint Arch., 2010)