English

Verifiable Homomorphic Linear Combinations in Multi-Instance Time-Lock Puzzles

Cryptography and Security 2024-08-23 v1 Distributed, Parallel, and Cluster Computing Machine Learning

Abstract

Time-Lock Puzzles (TLPs) have been developed to securely transmit sensitive information into the future without relying on a trusted third party. Multi-instance TLP is a scalable variant of TLP that enables a server to efficiently find solutions to different puzzles provided by a client at once. Nevertheless, existing multi-instance TLPs lack support for (verifiable) homomorphic computation. To address this limitation, we introduce the "Multi-Instance partially Homomorphic TLP" (MH-TLP), a multi-instance TLP supporting efficient verifiable homomorphic linear combinations of puzzles belonging to a client. It ensures anyone can verify the correctness of computations and solutions. Building on MH-TLP, we further propose the "Multi-instance Multi-client verifiable partially Homomorphic TLP" (MMH-TLP). It not only supports all the features of MH-TLP but also allows for verifiable homomorphic linear combinations of puzzles from different clients. Our schemes refrain from using asymmetric-key cryptography for verification and, unlike most homomorphic TLPs, do not require a trusted third party. A comprehensive cost analysis demonstrates that our schemes scale linearly with the number of clients and puzzles.

Keywords

Cite

@article{arxiv.2408.12444,
  title  = {Verifiable Homomorphic Linear Combinations in Multi-Instance Time-Lock Puzzles},
  author = {Aydin Abadi},
  journal= {arXiv preprint arXiv:2408.12444},
  year   = {2024}
}

Comments

arXiv admin note: text overlap with arXiv:2406.15070

R2 v1 2026-06-28T18:20:54.189Z