ACM ASIA Public-Key Cryptography Workshop (APKC)
Card-based Single-shuffle Protocols for Secure Multiple-input AND and XOR Computations
Tomoki Kuzuma, Raimu Isuzugawa, Kodai Toyoda, Daiki Miyahara, Takaaki Mizuki
Abstract
In card-based cryptography, the numbers of cards and shuffles are the complexity measures of protocols for secure computations, and the smaller these values are, the better. As the state-of-the-art study to minimize the latter measure, Shinagawa and Nuida showed a surprising result that any n-input logical function can be securely computed with only one shuffle, based on the idea of Yao's garbled circuit. When executing their protocol, the number of required cards is 2n+24q, where the n-input logical function to be computed is represented by q gates. For example, when applied to the n-input AND and XOR functions, the number of gates is n-1, and hence, 26n-24 cards are required. In this paper, we show that the number of required cards can be reduced by focusing on these two specific functions. Specifically, we construct a single-shuffle protocol for the n-input AND function using 4n-2 cards, and construct a single-shuffle protocol for the n-input XOR function using 2n cards.