Paper 2021/1038

Reinforced Concrete: A Fast Hash Function for Verifiable Computation

Lorenzo Grassi, Dmitry Khovratovich, Reinhard Lüftenegger, Christian Rechberger, Markus Schofnegger, and Roman Walch


We propose a new hash function Reinforced Concrete, which is the first generic purpose hash that is fast both for a zero-knowledge prover and in native x86 computations. It is suitable for a various range of zero-knowledge proofs and protocols, from set membership to generic purpose verifiable computation. Being up to 15x faster than its predecessor Poseidon hash, Reinforced Concrete inherits security from traditional time-tested schemes such as AES, whereas taking the zero-knowledge performance from a novel and efficient decomposition of a prime field into compact buckets. The new hash function is suitable for a wide range of applications like privacy-preserving cryptocurrencies, verifiable encryption, protocols with state membership proofs, or verifiable computation. It may serve as a drop-in replacement for various prime-field hashes such as variants of MiMC, Poseidon, Pedersen hash, and others.

Available format(s)
Secret-key cryptography
Publication info
Preprint. MINOR revision.
hash functionsverifiable computationzk- snarksfinite fields
Contact author(s)
L Grassi @ cs ru nl
khovratovich @ gmail com
reinhard lueftenegger @ iaik tugraz at
christian rechberger @ tugraz at
markus schofnegger @ tugraz at
roman walch @ iaik tugraz at
2022-05-19: last of 3 revisions
2021-08-16: received
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Creative Commons Attribution


      author = {Lorenzo Grassi and Dmitry Khovratovich and Reinhard Lüftenegger and Christian Rechberger and Markus Schofnegger and Roman Walch},
      title = {Reinforced Concrete: A Fast Hash Function for Verifiable Computation},
      howpublished = {Cryptology ePrint Archive, Paper 2021/1038},
      year = {2021},
      note = {\url{}},
      url = {}
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