Paper 2022/1169

DyCAPS: Asynchronous Proactive Secret Sharing for Dynamic Committees

Bin Hu, Beihang University
Zongyang Zhang, Beihang University
Han Chen, Beihang University
You Zhou, Beihang University
Huazu Jiang, Beihang University
Jianwei Liu, Beihang University

Dynamic-committee proactive secret sharing (DPSS) enables the update of secret shares and the alternation of shareholders without changing the secret. Such a proactivization functionality makes DPSS a promising technology for long-term key management and committee governance. Although non-asynchronous DPSS schemes have achieved cubic communication cost w.r.t. the number of shareholders, the overhead of asynchronous DPSS remains exponential. In this paper, we fill this gap and propose DyCAPS, an efficient asynchronous DPSS scheme with a cubic communication cost. DyCAPS can be efficiently integrated into asynchronous BFT protocols without increasing the overall asymptotic communication cost. Experimental results show that given a payload of 15 MB per party, DyCAPS achieves member change in Dumbo2 (CCS 2020) at the cost of 5%–22% throughput degradation, when the committee size varies from 4 to 22.

Available format(s)
Cryptographic protocols
Publication info
Proactive secret sharing Asynchronous dynamic committee BFT
Contact author(s)
hubin0205 @ buaa edu cn
zongyangzhang @ buaa edu cn
chenhan1123 @ buaa edu cn
youzhou @ buaa edu cn
anjhz @ buaa edu cn
liujianwei @ buaa edu cn
2022-12-04: revised
2022-09-07: received
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Creative Commons Attribution-NonCommercial


      author = {Bin Hu and Zongyang Zhang and Han Chen and You Zhou and Huazu Jiang and Jianwei Liu},
      title = {DyCAPS: Asynchronous Proactive Secret Sharing for Dynamic Committees},
      howpublished = {Cryptology ePrint Archive, Paper 2022/1169},
      year = {2022},
      note = {\url{}},
      url = {}
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