Information Theoretic Security with Interactive Communication

In our research group, we are studying information theory; in particular, we are studying problems that are related information security. Information technology has advanced significantly these days, and information security technology is becoming very important. One of the most widely used security technology is the so-called public cryptography, and its security is based on difficulty of certain mathematical problems. On the other hand, the security of information theoretic cryptography is proved without any assumption on computational power of attackers. However, to realize such a strong security system, the legitimate parties have to share some resource such as correlated observations. Thus, it is extremely important to use that resource to realize certain security tasks. In our research group, from the view point of information theory, we are pursuing to clarify the fundamental limit of the efficiency of realizing certain security tasks from a given resource. In particular, we are interested in protocols that involve interactive communication, and we are tackling those problems these days.