Efficient Verifiable Delay Functions

【Author】 Wesolowski, Benjamin

【Source】JOURNAL OF CRYPTOLOGY

【影响因子】1.691

【Abstract】We construct a verifiable delay function (VDF). A VDF is a function whose evaluation requires running a given number of sequential steps, yet the result can be efficiently verified. They have applications in decentralised systems, such as the generation of trustworthy public randomness in a trustless environment, or resource-efficient blockchains. To construct our VDF, we actually build atrapdoorVDF. A trapdoor VDF is essentially a VDF which can be evaluated efficiently by parties who know a secret (the trapdoor). By setting up this scheme in a way that the trapdoor is unknown (not even by the party running the setup, so that there is no need for a trusted setup environment), we obtain a simple VDF. Our construction is based on groups of unknown order such as an RSA group or the class group of an imaginary quadratic field. The output of our construction is very short (the result and the proof of correctness are each a single element of the group), and the verification of correctness is very efficient.

【Keywords】Time-lock puzzle; VDF; Randomness beacon; RSA; Class group

【发表时间】2020 OCT

【收录时间】2022-01-02

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