MiMC: Efficient Encryption and Cryptographic Hashing with Minimal Multiplicative Complexity

Martin Albrecht, Lorenzo Grassi, Christian Rechberger, Arnab Roy, Tyge Tiessen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

180 Downloads (Pure)


We explore cryptographic primitives with low multiplicative complexity. This is motivated by recent progress in practical applications of secure multi-party computation (MPC), fully homomorphic encryption (FHE), and zero-knowledge proofs (ZK) where primitives from symmetric cryptography are needed and where linear computations are, compared to non-linear operations, essentially “free”. Starting with the cipher design strategy “LowMC” from Eurocrypt 2015, a number of bit-oriented proposals have been put forward, focusing on applications where the multiplicative depth of the circuit describing the cipher is the most important optimization goal.

Surprisingly, albeit many MPC/FHE/ZK-protocols natively support operations in GF(p)GF(p) for large p, very few primitives, even considering all of symmetric cryptography, natively work in such fields. To that end, our proposal for both block ciphers and cryptographic hash functions is to reconsider and simplify the round function of the Knudsen-Nyberg cipher from 1995. The mapping F(x):=x3F(x):=x3 is used as the main component there and is also the main component of our family of proposals called “MiMC”. We study various attack vectors for this construction and give a new attack vector that outperforms others in relevant settings.

Due to its very low number of multiplications, the design lends itself well to a large class of applications, especially when the depth does not matter but the total number of multiplications in the circuit dominates all aspects of the implementation. With a number of rounds which we deem secure based on our security analysis, we report on significant performance improvements in a representative use-case involving SNARKs.
Original languageEnglish
Title of host publicationAdvances in Cryptology – ASIACRYPT 2016
Subtitle of host publication22nd International Conference on the Theory and Application of Cryptology and Information Security, Hanoi, Vietnam, December 4-8, 2016, Proceedings, Part I
Number of pages29
ISBN (Electronic)978-3-662-53887-6
ISBN (Print)978-3-662-53886-9
Publication statusE-pub ahead of print - 9 Nov 2016

Publication series

NameLecture Notes in Computer Science
PublisherSpringer Berlin Heidelberg
ISSN (Print)0302-9743

Cite this