抄録
Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), Category: Grant-in-Aid for Challenging Research (Exploratory), Fund Type: competitive_research_funding, Overall Grant Amount: - (direct: 4900000, indirect: 1470000)
In this study, we revisited the security proofs of cryptographic protocols from the viewpoint of logic and tried to understand them easily. As the tools for this purpose, we used so-called physical cryptography such as card-based protocols and private PEZ protocols, which have been studied extensively in recent years. Since the card-based protocols are based on the technique called a private permutation, the proposed protocols have a similar structure to ordinary (algebraic) multi-party computations. The security of private PEZ protocols is easier to understand compared to algebraic multi-party computations because it is free from simulation-based security. We proposed several new card-based and private PEZ protocols with higher efficiency, which contributed to understanding the security of cryptographic protocols simply. Some of these results have been published in international journals and major international conferences.