Paper 2021/1393
Fiat–Shamir Bulletproofs are Non-Malleable (in the Algebraic Group Model)
Chaya Ganesh and Claudio Orlandi and Mahak Pancholi and Akira Takahashi and Daniel Tschudi
Abstract
Bulletproofs (Bünz et al. IEEE S&P 2018) are a celebrated ZK proof system that allows for short and efficient proofs, and have been implemented and deployed in several real-world systems. In practice, they are most often implemented in their non-interactive version obtained using the Fiat-Shamir transform, despite the lack of a formal proof of security for this setting. Prior to this work, there was no evidence that malleability attacks were not possible against Fiat-Shamir Bulletproofs. Malleability attacks can lead to very severe vulnerabilities, as they allow an adversary to forge proofs re-using or modifying parts of the proofs provided by the honest parties. In this paper, we show for the first time that Bulletproofs (or any other similar multi-round proof system satisfying some form of weak unique response property) achieve simulation-extractability in the algebraic group model. This implies that Fiat-Shamir Bulletproofs are non-malleable.
Metadata
- Available format(s)
- Publication info
- Preprint. MINOR revision.
- Keywords
- Non-interactive Zero-knowledgeSimulation-extractabilityFiat-ShamirBulletproofs
- Contact author(s)
-
chaya @ iisc ac in
orlandi @ cs au dk
mahakp @ cs au dk
takahashi @ cs au dk
dt @ concordium com - History
- 2022-03-17: revised
- 2021-10-15: received
- See all versions
- Short URL
- https://ia.cr/2021/1393
- License
-
CC BY