Matsuura Lab aims at contribution of constructing social system where any non-specialist is able to communicate with others securely. Our main research fields conclude how to establish infrastructure of cryptology, information security and network protocol; and how to solve the problems that occur when such infrastructure is evolved or employed in society.

Keywords

• Public Key Cryptography, ID-based Cryptography, Broadcast Encryption, Key Management, Quantum Cryptography, Provable Security, Digital Signature, Hash Function

Cryptology is the necessary technology to construct social system where any non-specialist is able to communicate with others securely. Especially, recently this necessity becomes more and more obvious because cryptology is the foundation technique of the network security. We are working on not only developing efficient and practical cryptosystems, but also building frameworks for combining colorfully cryptosystems utilized with high functionality. One research example is "Forward-Secure and Searchable Broadcast Encryption with Short Ciphertexts and Private Keys", with published paper at ASIACRYPT'06. By employing such a scheme, one can process e-mails during transportation without being aware of any sensitive information. Other research fields can be listed as key exposure countermeasure, hybrid encryption, identity based encryption, quantum key exchange protocol for quantum cryptography, digital signature, et al.

Keywords

• IP Traceback, Netword Monitoring, Spam Mail Filtering
  

To communicate securely, the first condition is that the network must be available to be used. Moreover, we want to use it at ease. To satisfy the requirements, we study familiar techniques, for example, counter-measure against spam mail, fraud detection and tracing, etc. And some of our results achieved the best level of performance in the world.

Keywords

• Risk Management, Finance Engineering, Investment Theory

In total management of information security, considering human and social sides makes it become an extremely difficult problem. In many cases, the main reason is the uncertainty of economic risk. To deal with this problem, we introduce the financial engineering (option price evaluation, insurance, and investment theory) into the information security, and research the risk management theory that suits the networked society. Moreover, we do pioneering experimental study using reliable and large public data.