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Constant Ciphertext-Rate Non-committing Encryption from Standard Assumptions

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conference contribution
posted on 2023-11-29, 18:14 authored by Zvika Brakerski, Pedro Branco, Nico DöttlingNico Döttling, Sanjam Garg, Giulio Malavolta
Non-committing encryption (NCE) is a type of public key encryption which comes with the ability to equivocate ciphertexts to encryptions of arbitrary messages, i.e., it allows one to find coins for key generation and encryption which “explain” a given ciphertext as an encryption of any message. NCE is the cornerstone to construct adaptively secure multiparty computation [Canetti et al. STOC’96] and can be seen as the quintessential notion of security for public key encryption to realize ideal communication channels. A large body of literature investigates what is the best message-to-ciphertext ratio (i.e., the rate) that one can hope to achieve for NCE. In this work we propose a near complete resolution to this question and we show how to construct NCE with constant rate in the plain model from a variety of assumptions, such as the hardness of the learning with errors (LWE), the decisional Diffie-Hellman (DDH), or the quadratic residuosity (QR) problem. Prior to our work, constructing NCE with constant rate required a trusted setup and indistinguishability obfuscation [Canetti et al. ASIACRYPT’17].


Preferred Citation

Zvika Brakerski, Pedro Branco, Nico Döttling, Sanjam Garg and Giulio Malavolta. Constant Ciphertext-Rate Non-committing Encryption from Standard Assumptions. In: Theory of Cryptography Conference (TCC). 2020.

Primary Research Area

  • Algorithmic Foundations and Cryptography

Name of Conference

Theory of Cryptography Conference (TCC)

Legacy Posted Date


Open Access Type

  • Unknown


@inproceedings{cispa_all_3355, title = "Constant Ciphertext-Rate Non-committing Encryption from Standard Assumptions", author = "Brakerski, Zvika and Branco, Pedro and Döttling, Nico and Garg, Sanjam and Malavolta, Giulio", booktitle="{Theory of Cryptography Conference (TCC)}", year="2020", }

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