N-Choice Game: Building a Smart Contract for Accurate Pseudo-Random Number Generation

Abstract

We propose N-choice game (NCG), a decentralized method for generating pseudo-random numbers for smart contracts. NCG involves multiple participants, each of whom chooses a value between 0 and \(N-1\) and whose collective choices determine the generation of a pseudo-random number. The design of NCG has three key objectives: incentivizing participants to make random choices, assessing randomness in a decentralized environment, and achieving high operational performance. Implemented in Solidity and rigorously tested, NCG has shown remarkable effectiveness. Our results show that the randomness of the numbers generated by NCG is high and consistent, even under a strict NIST randomness test, provided that there is no collusion between the majority of participants. Not only is it impossible to customize the outputs generated by NCG, but it is also impractical to make them non-random. Therefore, it is rational to engage NCG for the purpose of rewards rather than the output values it produces. Selecting values in a way that is not predicted by other nodes yields the highest expected value, and NCG incentivizes random selection. Furthermore, NCG demonstrates a significant performance advantage, being up to 158 times faster at generating random numbers than the existing Random Bit Generator framework [ 3 ]. This efficiency underscores NCG’s potential to enhance blockchain applications.