How to avoid repetitions in lattice-based deniable zero-knowledge proofs
Interactive zero-knowledge systems are a very important cryptographic primitive, used in many applications, especially when deniability (also known as non-transferability) is desired. In the lattice-based setting, the currently most efficient interactive zero-knowledge systems employ the technique o...
| Autores: | , , , |
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| Tipo de recurso: | informe técnico |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/376989 |
| Acceso en línea: | https://hdl.handle.net/2117/376989 |
| Access Level: | acceso abierto |
| Palabra clave: | Information theory Coding theory zero-knowledge lattices rejection sampling deniability Informació, Teoria de la Codificació, Teoria de la Classificació AMS::94 Information And Communication, Circuits Àrees temàtiques de la UPC::Informàtica::Seguretat informàtica::Criptografia |
| Sumario: | Interactive zero-knowledge systems are a very important cryptographic primitive, used in many applications, especially when deniability (also known as non-transferability) is desired. In the lattice-based setting, the currently most efficient interactive zero-knowledge systems employ the technique of rejection sampling, which implies that the interaction does not always finish correctly in the first execution; the whole interaction must be re-run until abort does not happen. While repetitions due to aborts are acceptable in theory, in some practical applications it is desirable to avoid re-runs for usability reasons. In this work we present a generic technique that departs from an interactive zero-knowledge system (that might require multiple re-runs to complete the protocol) and obtains a 3-moves zero-knowledge system (without re-runs). The transformation combines the well-known Fiat-Shamir technique with a couple of initially exchanged messages. The resulting 3-moves system enjoys honest-verifier zero-knowledge and can be easily turned into a fully deniable proof using standard techniques. We show some practical scenarios where our transformation can be beneficial and we also discuss the results of an implementation of our transformation. |
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