  A Verifiable Delay Function (VDF) is a function that takes a specified
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 [6, 8] and
isogenies over pairing groups [4]. The number of modulo squaring required for
verification in the time-lock puzzle based VDFs are proportional to their
security parameter. This paper proposes a verifiable delay function that
requires only 2- modulo squaring for verification. So the sequential effort
required for verification is independent of the security parameter.
