The focus of our research is on card-based cryptography.
Card-based cryptography uses a physical deck of cards such as playing cards to perform cryptographic functionalities such as secure computations and zero-knowledge proofs. Since Bert den Boer proposed a protocol (called the five-card trick) for a secure computation of the logical AND function using five cards in 1989, papers from abroad were published sporadically until about 2001. Professor Mizuki started publishing papers on card-based cryptography around 2006, and mathematically established a computational model for card-based cryptographic protocols. The number of researchers entering this field has increased and its development is ongoing.
Specific efforts in this laboratory include: designing and developing efficient card-based cryptographic protocols for secure computations and clarifying their computational limits; devising card-based cryptographic protocols for zero-knowledge proofs; refining the computational model of card-based cryptographic protocols and developing them for practical use; and investigating the use of familiar tools other than decks of cards.