Paper 2014/829

Additively Homomorphic UC commitments with Optimal Amortized Overhead

Ignacio Cascudo, Ivan Damgård, Bernardo David, Irene Giacomelli, Jesper Buus Nielsen, and Roberto Trifiletti


We propose the first UC secure commitment scheme with (amortized) computational complexity linear in the size of the string committed to. After a preprocessing phase based on oblivious transfer, that only needs to be done once and for all, our scheme only requires a pseudorandom generator and a linear code with efficient encoding. We also construct an additively homomorphic version of our basic scheme using VSS. Furthermore we evaluate the concrete efficiency of our schemes and show that the amortized computational overhead is significantly lower than in the previous best constructions. In fact, our basic scheme has amortised concrete efficiency comparable with previous protocols in the Random Oracle Model even though it is constructed in the plain model.

Note: Full version of the paper appeared in PKC2015

Available format(s)
Cryptographic protocols
Publication info
Published by the IACR in PKC 2015
universal composabilitycommitmentVSSsecret sharingcodingasymptotics
Contact author(s)
giacomelli @ cs au dk
2015-01-11: last of 2 revisions
2014-10-13: received
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      author = {Ignacio Cascudo and Ivan Damgård and Bernardo David and Irene Giacomelli and Jesper Buus Nielsen and Roberto Trifiletti},
      title = {Additively Homomorphic {UC} commitments with Optimal Amortized Overhead},
      howpublished = {Cryptology ePrint Archive, Paper 2014/829},
      year = {2014},
      note = {\url{}},
      url = {}
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