51 citations · 330 across the 30 of their papers we have counts for
31 papers
Card-Based Computation in the Virtual Player Simulation Model
Suthee Ruangwises
Player simulation has recently emerged as a new direction in card-based cryptography, with protocols developed for simulating virtual players in physical card games such as Old Mai…
Cyclic Equalizability Characterized by Parikh Vectors
Sarunyu Thongjarast, Sarit Pasiphol, Suthee Ruangwises
Cyclic equalizability is a notion introduced by Shinagawa and Nuida in 2025, in the study of card-based cryptography. Informally, a collection of words is cyclically equalizable if…
A Complexity Hierarchy of Shuffles in Card-Based Protocols
Tomoki Ono, Suthee Ruangwises
Card-based cryptography uses physical playing cards to construct protocols for secure multi-party computation. Existing card-based protocols employ various types of shuffles, some…
Wataridori is NP-Complete
Suthee Ruangwises
Wataridori is a pencil puzzle that involves drawing paths in a rectangular grid to connect circles into pairs while satisfying several constraints. In this paper, we prove that dec…
NP-Completeness Proofs of All or Nothing, Water Walk, and Remembered Length Using the T-Metacell Framework
Pakapim Eua-anant, Papangkorn Apinyanon, Thunyatorn Jirachaisri +2
All or Nothing, Water Walk, and Remembered Length are pencil puzzles that involve constructing a continuous loop on a rectangular grid under specific constraints. In this paper, we…
NP-Completeness Proofs of Puzzles using the T-Metacell Framework
Nattapol Kiatchaipipat, Suthee Ruangwises
Pencil puzzles are puzzles that can be solved by writing down solutions on a paper, using only logical reasoning. In this paper, we utilize the "T-metacell" framework developed by…
Simulating Virtual Players for UNO without Computers
Suthee Ruangwises, Kazumasa Shinagawa
UNO is a popular multiplayer card game. In each turn, a player has to play a card in their hand having the same number or color as the most recently played card. When having few pe…
Balance-Based Cryptography: Physically Computing Any Boolean Function
Suthee Ruangwises
Secure multi-party computation is an area in cryptography which studies how multiple parties can compare their private information without revealing it. Besides digital protocols,…
NP-Completeness and Physical Zero-Knowledge Proofs for Zeiger
Suthee Ruangwises
Zeiger is a pencil puzzle consisting of a rectangular grid, with each cell having an arrow pointing in horizontal or vertical direction. Some cells also contain a positive integer.…
Tatami Printer: Physical ZKPs for Tatami Puzzles
Suthee Ruangwises
Tatami puzzles are pencil puzzles with an objective to partition a rectangular grid into rectangular regions such that no four regions share a corner point, as well as satisfying o…
Card-Based Overwriting Protocol for Equality Function and Applications
Suthee Ruangwises, Tomoki Ono, Yoshiki Abe +2
Research in the area of secure multi-party computation with an unconventional method of using a physical deck of playing cards began in 1989 when den Boer proposed a protocol to co…
Nondango is NP-Complete
Suthee Ruangwises
Nondango is a pencil puzzle consisting of a rectangular grid partitioned into regions, with some cells containing a white circle. The player has to color some circles black such th…
Sumplete is Hard, Even with Two Different Numbers
Suthee Ruangwises
Sumplete is a logic puzzle famous for being developed by ChatGPT. The puzzle consists of a rectangular grid, with each cell containing a number. The player has to cross out some nu…
The Landscape of Computing Symmetric -Variable Functions with Cards
Suthee Ruangwises
Secure multi-party computation using a physical deck of cards, often called card-based cryptography, has been extensively studied during the past decade. Card-based protocols to co…
Verifying the First Nonzero Term: Physical ZKPs for ABC End View, Goishi Hiroi, and Toichika
Suthee Ruangwises
In this paper, we propose a physical protocol to verify the first nonzero term of a sequence using a deck of cards. The protocol lets a prover show the value of the first nonzero t…
Physical Zero-Knowledge Proof for Ball Sort Puzzle
Suthee Ruangwises
Ball sort puzzle is a popular logic puzzle consisting of several bins containing balls of multiple colors. Each bin works like a stack; a ball has to follow the last-in first-out o…
Printing Protocol: Physical ZKPs for Decomposition Puzzles
Suthee Ruangwises, Mitsugu Iwamoto
Decomposition puzzles are pencil-and-paper logic puzzles that involve partitioning a rectangular grid into several regions to satisfy certain rules. In this paper, we construct a g…
How to Physically Verify a Rectangle in a Grid: A Physical ZKP for Shikaku
Suthee Ruangwises, Toshiya Itoh
Shikaku is a pencil puzzle consisting of a rectangular grid, with some cells containing a number. The player has to partition the grid into rectangles such that each rectangle cont…
Physical ZKP for Makaro Using a Standard Deck of Cards
Suthee Ruangwises, Toshiya Itoh
Makaro is a logic puzzle with an objective to fill numbers into a rectangular grid to satisfy certain conditions. In 2018, Bultel et al. developed a physical zero-knowledge proof (…
An Improved Physical ZKP for Nonogram and Nonogram Color
Suthee Ruangwises
Nonogram is a pencil puzzle consisting of a rectangular white grid where the player has to paint some cells black according to given constraints. In 2010, Chien and Hon constructed…
Two Standard Decks of Playing Cards are Sufficient for a ZKP for Sudoku
Suthee Ruangwises
Sudoku is a famous logic puzzle where the player has to fill a number between 1 and 9 into each empty cell of a grid such that every number appears exactly once in eac…
Using Five Cards to Encode Each Integer in
Suthee Ruangwises
Research in secure multi-party computation using a deck of playing cards, often called card-based cryptography, dates back to 1989 when Den Boer introduced the "five-card trick" to…
Physical ZKP for Connected Spanning Subgraph: Applications to Bridges Puzzle and Other Problems
Suthee Ruangwises, Toshiya Itoh
An undirected graph is known to both the prover and the verifier , but only knows a subgraph of . Without revealing any information about , wants to co…
Physical Zero-Knowledge Proof for Ripple Effect
Suthee Ruangwises, Toshiya Itoh
Ripple Effect is a logic puzzle where the player has to fill numbers into empty cells in a rectangular grid. The grid is divided into rooms, and each room must contain consecutive…