Single-Shuffle Card-Based Protocols with Six Cards per Gate

Card-based cryptography refers to a secure computation with physical cards, and the number of cards and shuffles measures the efficiency of card-based protocols. This paper proposes new card-based protocols for any Boolean circuits with only a single shuffle. Although our protocols rely on Yao’s garbled circuit as in previous single-shuffle card-based protocols, our core construction idea is to encode truth tables of each Boolean gate with fewer cards than previous works while being compatible with Yao’s garbled circuit. As a result, we show single-shuffle card-based protocols with six cards per gate, which are more efficient than previous single-shuffle card-based protocols.