A Verifiable Delay Function (VDF) is a function that takes a specified (typically long) sequential time to be evaluated, but can be efficiently verified. VDFs are useful in several applications ranging from randomness beacons to sustainable blockchains but are really rare in practice. Most of the VDFs are based on algebraic assumptions like time-lock puzzle in unknown group orders [7,9] and isogenies over pairing groups [4]. The time-lock puzzle based VDFs require effort proportional to their security parameter during their verifications. This paper proposes a verifiable delay function that requires fixed effort during verification. Also this effort to verify is independent of the security parameter of the scheme

翻译：可核实延迟函数( VDF) 是一个函数, 需要特定( 通常长的) 相继时间来进行评估, 但可以有效核实。 VDF 可用于从随机信标到可持续链条等多个应用程序, 但实际上非常少见。 大多数 VDF 是基于代数假设的, 如未知组号中的时间锁定拼图 [7, 9] 和配对组[4] 。 以时间锁定拼图为基础的 VDF 要求在核查期间根据安全参数做出相应的努力。 本文提出一个可核查的延迟功能, 需要在核查期间做出固定的努力。 此外, 核查工作独立于计划的安全参数 。