Our Research.

In our laboratory, we have conducted research on various topics, including cryptography based on mathematical theory, and informationsecurity research such as threat analysis of recent technologies.

Current Research Theme.

Security for AI.

Although AI has been used in various situations, we have studied the security ofAI itself. For example, there are known attacks to make a piracy of AI throughAPI of AI. We will shed light on potential threats of AI by exploring new attacksand countermeasures.

Blockchain.

Blockchain is expected to be applied not only to cryptocurrencies such asBitcoin, but also to various distributed technologies through programmingplatforms. We aim to develop safe and secure distributed applications throughthe development of blockchain technologies and the analysis of blockchainprograms.

Secure Network Configuration.

By sending out false information when constructing a network, it is possible foran adversary to connect to a fake device installed by the adversary and stealinformation. For countermeasures on this situation, we have conducted researchand development to increase the reliability of the network itself byguaranteeing the validity of the network information.

Cryptography with Advanced Functionality.

There are a lot of cryptographic primitives that achieve higher functionality than conventional ones, such as aggregate signature schemes, identity-based encryption schemes, zero-knowledge proof systems, etc. We propose new construction of them, or improve the efficiency of existing schemes.

Theory of cryptography.

We study theoretical aspects of cryptographic primitives, i.e., black-box reduction of primitives. There are many theoretical properties that are not yet known even for primitives that have been known for a long time, and we uncover such unknown properties.