Multi-instance Publicly Verifiable Time-Lock Puzzle and Its Applications

Time-lock puzzles are elegant protocols that enable a party to lock message such no one else can unlock it until certain time elapses. Nevertheless, existing schemes not suitable for the case where server is given multiple instances of puzzle scheme at once and must them different points in time. If naively used this setting, then has start solving all as soon receives them, ultimately imposes significant computation cost demands high level parallelisation. We put forth formally define primitive called “multi-instance time-lock puzzle” which allows composing puzzle’s instances. propose candidate construction: “chained (C-TLP). It server, instances’ composition, solve sequentially, without having run parallel computations on them. C-TLP makes black-box use standard accompanied by lightweight publicly verifiable algorithm. first offers combination above features. build “outsourced proofs retrievability” support real-time detection fair payment while lower overhead than state art. As another application C-TLP, we illustrate cases, substitute “verifiable delay function” with gain much better efficiency.