Constant Ciphertext-Rate Non-Committing Encryption from Standard Assumptions
Constant Ciphertext-Rate Non-Committing Encryption from Standard Assumptions
复制标题
标准假设的恒定密文率非提交加密
DOI：
10.1007/978-3-030-64375-1_3
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Giulio Malavolta
中科院分区：
文献类型：
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作者：
Zvika Brakerski;P. Branco;Nico Döttling;Sanjam Garg;Giulio Malavolta
非提交加密（NCE）是一种公钥加密，它具有将密文模棱两可地加密为任意消息的能力，即，它允许人们找到用于密钥生成和加密的硬币，将给定的密文“解释”为任何消息的加密。 NCE 是构建自适应安全多方计算的基石 [Canetti 等人。 STOC’96]，可以被视为公钥加密实现理想通信通道的典型安全概念。大量文献研究了 NCE 希望达到的最佳消息与密文比率（即比率）。在这项工作中，我们提出了这个问题的近乎完整的解决方案，并展示了如何根据各种假设，例如带错误学习的难度 (LWE) 或决策性 Diffie-Hellman (DDH)，在普通模型中构造恒定速率的 NCE。在我们的工作之前，以恒定速率构建 NCE 需要可信设置和不可区分性混淆 [Canetti 等人。 ASIACRYPT'17]。
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) or the decisional Diffie-Hellman (DDH). Prior to our work, constructing NCE with constant rate required a trusted setup and indistinguishability obfuscation [Canetti et al. ASIACRYPT’17].