Paper 2019/1300

Actively Secure Setup for SPDZ

Dragos Rotaru, Nigel P. Smart, Titouan Tanguy, Frederik Vercauteren, and Tim Wood


We present an actively secure, practical protocol to generate the distributed secret keys needed in the SPDZ offline protocol. The resulting distribution of the public and secret keys is such that the associated SHE `noise' analysis is the same as if the distributed keys were generated by a trusted setup. We implemented the presented protocol for distributed BGV key generation within the SCALE-MAMBA framework. Our method makes use of a new method for creating doubly (or even more) authenticated bits in different MPC engines, which has applications in other areas of MPC-based secure computation. We were able to generate keys for two parties and a plaintext size of 64 bits in around five minutes, and approximately eighteen minutes for a 128 bit prime.

Note: Made things a even more clearer

Available format(s)
Cryptographic protocols
Publication info
Published by the IACR in Joc 2022
MPCSomewhat Homomorphic EncryptionKey Generation
Contact author(s)
dragos @ capeprivacy com
nigel smart @ kuleuven be
titouan tanguy @ kuleuven be
frederik vercauteren @ esat kuleuven be
twood1089 @ gmail com
2021-11-17: last of 7 revisions
2019-11-11: received
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Creative Commons Attribution


      author = {Dragos Rotaru and Nigel P.  Smart and Titouan Tanguy and Frederik Vercauteren and Tim Wood},
      title = {Actively Secure Setup for SPDZ},
      howpublished = {Cryptology ePrint Archive, Paper 2019/1300},
      year = {2019},
      note = {\url{}},
      url = {}
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