Competitive Decentralized Randomness Beacon Protocols

Competitive Decentralized Randomness Beacon Protocols

연구 분야: Infrastructure

학회: BSCI '22: Proceedings of the Fourth ACM International Symposium on Blockchain and Secure Critical Infrastructure

A distributed and reliable source of randomness is always a critical element in cryptography, both in the construction and application of cryptographic primitives. Modern cryptography such as blockchain, cryptocurrencies, decentralized finance is heavily dependent on a trusted randomness source. In particular, Decentralized Randomness Beacon (DRB) protocols can be a reliable source of randomness. A DRB protocol generates a continuous stream of publicly verifiable random values. Almost all the available DRB protocols are collaborative in nature where participants of a DRB protocol collaborate their local entropy to generate global randomness. A DRB protocol can also be competitive where the participants compete to generate the global randomness. RANDCHAIN (ePrint 2020/1033) is the first Competitive Decentralized Randomness Beacon Protocol. Although RANDCHAIN claims to provide fairness and scalability, it still has a few problems concerning blockchain-oriented attacks and fairness to the participants. Therefore, to solve the existing problems of RANDCHAIN, we present a general model to construct competitive DRB protocols. Our competitive DRB model is a composition of committee selection strategy followed by a moderately hard cryptographic puzzle. To provide different levels of fairness, we present a variety of committee selection strategies. Our competitive DRB protocols provide better fairness, linear communication complexity, and better scalability compared to the existing DRB protocols.