Paper 2019/197

Non-interactive Cryptographic Timestamping based on Verifiable Delay Functions

Esteban Landerreche, Marc Stevens, and Christian Schaffner


We present the first treatment of non-interactive publicly-verifiable timestamping schemes in the Universal Composability framework. Similar to a simple construction by Mahmoody et al., we use non-parallelizable computational work that relates to elapsed time to avoid previous impossibility results on non-interactive timestamping. We extend these ideas to the UC-framework and show how to model verifiable delay functions (VDF) related to a global clock, and non-interactive timestamping, in the UC-framework. Furthermore, we present new constructions that are substantial improvements over Mahmoody et al.’s construction, such that any forged timestamps by the adversary are now limited to within a certain time-window that depends only on its ratio to compute VDFs more quickly and the time-window of corruption. Finally, we discuss natural applications for our construction in decentralized protocols.

Available format(s)
Publication info
Preprint. MINOR revision.
non-interactive cryptographic timestampinguniversal composabilityverifiable delay functionstime-lock cryptography
Contact author(s)
esteban @ cwi nl
2019-02-27: revised
2019-02-27: received
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Creative Commons Attribution


      author = {Esteban Landerreche and Marc Stevens and Christian Schaffner},
      title = {Non-interactive Cryptographic Timestamping based on Verifiable Delay Functions},
      howpublished = {Cryptology ePrint Archive, Paper 2019/197},
      year = {2019},
      note = {\url{}},
      url = {}
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