Paper 2020/084

Bandwidth-efficient threshold EC-DSA

Guilhem Castagnos, Dario Catalano, Fabien Laguillaumie, Federico Savasta, and Ida Tucker


Threshold Signatures allow n parties to share the power of issuing digital signatures so that any coalition of size at least (t+1) can sign, whereas groups of t or less players cannot. Over the last few years many schemes addressed the question of realizing efficient threshold variants for the specific case of EC-DSA signatures. In this paper we present new solutions to the problem that aim at reducing the overall bandwidth consumption. Our main contribution is a new variant of the Gennaro and Goldfeder protocol from ACM CCS 2018 that avoids all the required range proofs, while retaining provable security against malicious adver- saries in the dishonest majority setting. Our experiments show that – for all levels of security – our signing protocol reduces the bandwidth consumption of best previously known secure protocols for factors varying between 4.4 and 9, while key generation is consistently two times less expensive. Furthermore compared to these same protocols, our signature generation is faster for 192-bits of security and beyond.

Available format(s)
Cryptographic protocols
Publication info
Published elsewhere. Minor revision. PKC 2020
threshold signaturesECDSAclass groupsbandwidth efficient
Contact author(s)
ida tucker @ ens-lyon fr
2021-09-09: last of 2 revisions
2020-01-28: received
See all versions
Short URL
Creative Commons Attribution


      author = {Guilhem Castagnos and Dario Catalano and Fabien Laguillaumie and Federico Savasta and Ida Tucker},
      title = {Bandwidth-efficient threshold {EC}-{DSA}},
      howpublished = {Cryptology ePrint Archive, Paper 2020/084},
      year = {2020},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.