3 Search Results for "Itoh, Toshiya"


Document
How to Physically Verify a Rectangle in a Grid: A Physical ZKP for Shikaku

Authors: Suthee Ruangwises and Toshiya Itoh

Published in: LIPIcs, Volume 226, 11th International Conference on Fun with Algorithms (FUN 2022)


Abstract
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 contains exactly one number equal to the area of that rectangle. In this paper, we propose two physical zero-knowledge proof protocols for Shikaku using a deck of playing cards, which allow a prover to physically show that he/she knows a solution of the puzzle without revealing it. Most importantly, in our second protocol we develop a general technique to physically verify a rectangle-shaped area with a certain size in a rectangular grid, which can be used to verify other problems with similar constraints.

Cite as

Suthee Ruangwises and Toshiya Itoh. How to Physically Verify a Rectangle in a Grid: A Physical ZKP for Shikaku. In 11th International Conference on Fun with Algorithms (FUN 2022). Leibniz International Proceedings in Informatics (LIPIcs), Volume 226, pp. 24:1-24:12, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)


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@InProceedings{ruangwises_et_al:LIPIcs.FUN.2022.24,
  author =	{Ruangwises, Suthee and Itoh, Toshiya},
  title =	{{How to Physically Verify a Rectangle in a Grid: A Physical ZKP for Shikaku}},
  booktitle =	{11th International Conference on Fun with Algorithms (FUN 2022)},
  pages =	{24:1--24:12},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-232-7},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{226},
  editor =	{Fraigniaud, Pierre and Uno, Yushi},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FUN.2022.24},
  URN =		{urn:nbn:de:0030-drops-159947},
  doi =		{10.4230/LIPIcs.FUN.2022.24},
  annote =	{Keywords: Zero-knowledge proof, Card-based cryptography, Shikaku, Puzzles, Games}
}
Document
On Basing Auxiliary-Input Cryptography on NP-Hardness via Nonadaptive Black-Box Reductions

Authors: Mikito Nanashima

Published in: LIPIcs, Volume 185, 12th Innovations in Theoretical Computer Science Conference (ITCS 2021)


Abstract
Constructing one-way functions based on NP-hardness is a central challenge in theoretical computer science. Unfortunately, Akavia et al. [Akavia et al., 2006] presented strong evidence that a nonadaptive black-box (BB) reduction is insufficient to solve this challenge. However, should we give up such a central proof technique even for an intermediate step? In this paper, we turn our eyes from standard cryptographic primitives to weaker cryptographic primitives allowed to take auxiliary-input and continue to explore the capability of nonadaptive BB reductions to base auxiliary-input primitives on NP-hardness. Specifically, we prove the followings: - if we base an auxiliary-input pseudorandom generator (AIPRG) on NP-hardness via a nonadaptive BB reduction, then the polynomial hierarchy collapses; - if we base an auxiliary-input one-way function (AIOWF) or auxiliary-input hitting set generator (AIHSG) on NP-hardness via a nonadaptive BB reduction, then an (i.o.-)one-way function also exists based on NP-hardness (via an adaptive BB reduction). These theorems extend our knowledge on nonadaptive BB reductions out of the current worst-to-average framework. The first result provides new evidence that nonadaptive BB reductions are insufficient to base AIPRG on NP-hardness. The second result also yields a weaker but still surprising consequence of nonadaptive BB reductions, i.e., a one-way function based on NP-hardness. In fact, the second result is interpreted in the following two opposite ways. Pessimistically, it shows that basing AIOWF or AIHSG on NP-hardness via nonadaptive BB reductions is harder than constructing a one-way function based on NP-hardness, which can be regarded as a negative result. Note that AIHSG is a weak primitive implied even by the hardness of learning; thus, this pessimistic view provides conceptually stronger limitations than the currently known limitations on nonadaptive BB reductions. Optimistically, it offers a new hope: breakthrough construction of auxiliary-input primitives might also provide construction standard cryptographic primitives. This optimistic view enhances the significance of further investigation on constructing auxiliary-input or other intermediate cryptographic primitives instead of standard cryptographic primitives.

Cite as

Mikito Nanashima. On Basing Auxiliary-Input Cryptography on NP-Hardness via Nonadaptive Black-Box Reductions. In 12th Innovations in Theoretical Computer Science Conference (ITCS 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 185, pp. 29:1-29:15, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)


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@InProceedings{nanashima:LIPIcs.ITCS.2021.29,
  author =	{Nanashima, Mikito},
  title =	{{On Basing Auxiliary-Input Cryptography on NP-Hardness via Nonadaptive Black-Box Reductions}},
  booktitle =	{12th Innovations in Theoretical Computer Science Conference (ITCS 2021)},
  pages =	{29:1--29:15},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-177-1},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{185},
  editor =	{Lee, James R.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITCS.2021.29},
  URN =		{urn:nbn:de:0030-drops-135686},
  doi =		{10.4230/LIPIcs.ITCS.2021.29},
  annote =	{Keywords: Auxiliary-input cryptographic primitives, nonadaptive black-box reductions}
}
Document
Physical Zero-Knowledge Proof for Numberlink

Authors: Suthee Ruangwises and Toshiya Itoh

Published in: LIPIcs, Volume 157, 10th International Conference on Fun with Algorithms (FUN 2021) (2020)


Abstract
Numberlink is a logic puzzle for which the player has to connect all pairs of cells with the same numbers by non-crossing paths in a rectangular grid. In this paper, we propose a physical protocol of zero-knowledge proof for Numberlink using a deck of cards, which allows a player to physically show that he/she knows a solution without revealing it. In particular, we develop a physical protocol to count the number of elements in a list that are equal to a given secret value without revealing that value, the positions of elements in the list that are equal to it, or the value of any other element in the list. Our protocol can also be applied to verify the existence of vertex-disjoint paths connecting all given pairs of endpoints in any undirected graph.

Cite as

Suthee Ruangwises and Toshiya Itoh. Physical Zero-Knowledge Proof for Numberlink. In 10th International Conference on Fun with Algorithms (FUN 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 157, pp. 22:1-22:11, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Copy BibTex To Clipboard

@InProceedings{ruangwises_et_al:LIPIcs.FUN.2021.22,
  author =	{Ruangwises, Suthee and Itoh, Toshiya},
  title =	{{Physical Zero-Knowledge Proof for Numberlink}},
  booktitle =	{10th International Conference on Fun with Algorithms (FUN 2021)},
  pages =	{22:1--22:11},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-145-0},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{157},
  editor =	{Farach-Colton, Martin and Prencipe, Giuseppe and Uehara, Ryuhei},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FUN.2021.22},
  URN =		{urn:nbn:de:0030-drops-127836},
  doi =		{10.4230/LIPIcs.FUN.2021.22},
  annote =	{Keywords: Zero-knowledge proof, Card-based cryptography, Numberlink, Puzzles, Games}
}
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