Cryptography, Complexity Theory, Algorithm Theory

Public-Key Cryptography, Provable Security, Advanced Cryptography, Post Quantum Cryptography

(1) Construction of Advanced Cryptography:
Advanced cryptography refers to cryptography that extends conventional cryptography with additional useful functionalities. An example is fully homomorphic encryption. Fully homomorphic encryption is a cryptographic technique that enables computations to be performed directly on encrypted data without decryption, making it possible to compute statistical data while preserving privacy. In our laboratory, we work on defining security models for advanced cryptography, constructing schemes, and proving their security.
(2) Construction of Post-Quantum Cryptography:
Post-quantum cryptography refers to cryptography that can run on classical computers and is difficult for quantum computers to break. In the future, quantum computers will be able to handle a large number of qubits. This will compromise the security of currently used cryptosystems such as RSA. Therefore, the development of post-quantum cryptography is essential. In our laboratory, we focus on constructing cryptographic schemes based on the hardness of problems related to lattices and error-correcting codes.

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Ordered Multi-Signatures with Public-Key Aggregation from SXDH Assumption. IWSEC 2025, Proceedings, volume 16208 of Lecture Notes in Computer Science, pages 67–87.
Public Key Encryption with Equality Test from Tag-Based Encryption. IWSEC 2025, Proceedings, volume 16208 of Lecture Notes in Computer Science, pages 24–44.
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