Security Amplification for InteractiveCryptographic Primitives
Security Amplification for InteractiveCryptographic Primitives
复制标题
交互式加密原语的安全增强
DOI：
10.1007/978-3-642-00457-5_9
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Valentine Kabanets
中科院分区：
文献类型：
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作者：
Y. Dodis;R. Impagliazzo;Ragesh Jaiswal;Valentine Kabanets
安全性放大是密码学中的一个重要问题：从某种密码原语的“弱安全”变体开始，目标是构建同一原语的“强安全”变体。这个问题已经成功地研究了各种重要的密码原语，如单向函数、抗碰撞哈希函数、加密方案和弱可验证谜题。然而，所有这些任务都是非交互式的。在这项工作中，我们研究了交互式密码原语的安全放大，如消息认证码（mac），数字签名（SIGs）和伪随机函数（prf）。特别地，我们证明了mac / sig的直接积定理和PRFs的异或引理，从而获得了这些原语的几乎最优的安全性放大。
Security amplification is an important problem in Cryptography: starting with a "weakly secure" variant of some cryptographic primitive, the goal is to build a "strongly secure" variant of the same primitive. This question has been successfully studied for a variety of important cryptographic primitives, such as one-way functions, collision-resistant hash functions, encryption schemes and weakly verifiable puzzles. However, all these tasks were non-interactive. In this work we study security amplification of interactive cryptographic primitives, such as message authentication codes (MACs), digital signatures (SIGs) and pseudorandom functions (PRFs). In particular, we prove direct product theorems for MACs/SIGs and an XOR lemma for PRFs, therefore obtaining nearly optimal security amplification for these primitives.
Our main technical result is a new Chernoff-type theorem for what we call Dynamic Weakly Verifiable Puzzles , which is a generalization of ordinary Weakly Verifiable Puzzles which we introduce in this paper.