Paper 2022/524

Inner Product Functional Commitments with Constant-Size Public Parameters and Openings

Hien Chu, Dario Fiore, Dimitris Kolonelos, and Dominique Schröder


Functional commitments (Libert et al.~[ICALP'16]) allow a party to commit to a vector $\vec v$ of length $n$ and later open the commitment at functions of the committed vector succinctly, namely with communication logarithmic or constant in $n$. Existing constructions of functional commitments rely on trusted setups and have either $O(1)$ openings and $O(n)$ parameters, or they have short parameters generatable using public randomness but have $O(\log n)$-size openings. In this work, we ask whether it is possible to construct functional commitments in which both parameters and openings can be of constant size. Our main result is the construction of the first FC schemes matching this complexity. Our constructions support the evaluation of inner products over small integers; they are built using groups of unknown order and rely on succinct protocols over these groups that are secure in the generic group and random oracle model.

Available format(s)
Public-key cryptography
Publication info
Preprint. MINOR revision.
CommitmentsFunctional CommitmentsSuccinct Arguments
Contact author(s)
hien chu @ fau de
dario fiore @ imdea org
dimitris kolonelos @ imdea org
dominique schroeder @ fau de
2022-05-10: received
Short URL
Creative Commons Attribution


      author = {Hien Chu and Dario Fiore and Dimitris Kolonelos and Dominique Schröder},
      title = {Inner Product Functional Commitments with Constant-Size Public Parameters and Openings},
      howpublished = {Cryptology ePrint Archive, Paper 2022/524},
      year = {2022},
      note = {\url{}},
      url = {}
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