A Survey on Proof of Sequential Work: Development, Security Analysis, and Application Prospects

Proof of sequential work (PoSW), as an emerging cryptographic primitive, is designed to provide a verifiable method for proving that a computational process has incurred a real and continuous expenditure of time. This characteristic demonstrates its significant application potential in decentralized systems, time-stamping services, and trusted computing. This paper systematically reviews and discusses the developmental trajectory, typical variants, potential attacks, and diverse applications of PoSW. Concurrently, it places a special emphasis on analyzing the evolutionary path and application scenarios of its important special case-the verifiable delay function (VDF) aiming to provide a comprehensive reference for research and practice in related fields.