He graduated from the department of Technology, Keio University in 1984, and joined Hitachi Ltd. He has been a Professor of the School of Computer Science, Tokyo University of Technology since 2009. Since April 2016, he is a Project Professor at Keio University. 

He received the 2004 IPSJ Best Paper Award, the 2008 IPSJ Best Paper Award, the IEEE-IIHMSP2006 Best Paper Award, and the 2013 Information Security Cultural Award.

In government related organizations, he is a Commissioner of Personal Information Protection Commission, a SIP Sub Program Director of Council for Science, Technology and Innovation, a Committee Member of Critical Infrastructure Advisory in Cybersecurity Strategy Headquarters Information Security Policy Meeting, an Task Force Member of IT Strategy Headquarters Electronic Administration, a Working Group Member of Related Information Infrastructure Technology, a Member of Basic Resident Register Network Research Committee, and a CRYPTREC Member. He is also a Chairperson of the Electronic Signature Law Working Group.

He is the President of the Information Network Law Association, an executive director of the Japan Society of Security Management and a director of the Institute of Digital Forensics.

His books include “Q&A Security Countermeasures for My Number (Seibunsha)”,  “Electronic Signature and Authentication using My Number (Nikkei BP) ”, “Enterprise Codes make Japan Strong: Another Type of Individual Number, the“Corporate Number（Nikkei BP）” and “Basic Information Security（Kyoritsu Shuppan）”.