Delay Function with Fixed Effort Verification

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