Constrained Keys for Invertible Pseudorandom Functions
Constrained Keys for Invertible Pseudorandom Functions
复制标题
可逆伪随机函数的约束键
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
David J. Wu
中科院分区：
文献类型：
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作者：
D. Boneh;Sam Kim;David J. Wu
约束伪随机函数(PRF)是一种安全的PRF，对于该PRF，人们可以生成仅可用于对域的子集上的PRF进行评估的约束密钥。约束PRF被广泛使用，最显著的是在不可分辨混淆((imathal{O}))的应用中。在这篇文章中，我们展示了如何约束一个可逆的PRF(IPF)，这要困难得多。IPF是一种安全的内射PRF，伴随着一种求逆算法。IPF的约束密钥只能用来计算域的子集S上的IPF，以及求S的像上的IPF。我们首先定义了约束IPF的概念，然后给出了两种主要构造：一种用于穿孔IPF，另一种用于(单密钥)电路约束。这两种构造都依赖于最近关于私有约束PRF的工作。我们还证明了在我们的定义下，许多约束类的约束伪随机置换是不可能的。
A constrained pseudorandom function (PRF) is a secure PRF for which one can generate constrained keys that can only be used to evaluate the PRF on a subset of the domain. Constrained PRFs are used widely, most notably in applications of indistinguishability obfuscation ((imathcal {O})). In this paper we show how to constrain an invertible PRF (IPF), which is significantly harder. An IPF is a secure injective PRF accompanied by an inversion algorithm. A constrained key for an IPF can only be used to evaluate the IPF on a subset S of the domain, and to invert the IPF on the image of S. We first define the notion of a constrained IPF and then give two main constructions: one for puncturing an IPF and the other for (single-key) circuit constraints. Both constructions rely on recent work on private constrained PRFs. We also show that constrained pseudorandom permutations for many classes of constraints are impossible under our definition.