Description
Robert recently described a powerful correspondence between certain (Hermitian) modules and (polarized) abelian varieties, which simultaneously generalizes both the class-group action underlying protocols such as CSIDH, and the Deuring correspondence, underlying protocols such as SQIsign. Using this correspondence, he also proposed how to construct a post-quantum NIKE, called MIKE, which, at a high level, can be viewed as a generalization of the Diffie-Hellman key exchange, based on a commutative monoidal action.
In the first part of the talk, we axiomatize the notion of a cryptographic monoidal action, giving a simpler (but less expressive) framework for constructing novel post-quantum protocols, which can be instantiated with Robert's correspondence. The potential advantage of cryptographic monoidal actions over cryptographic group actions is that, conjecturally, the associated hard problems do not admit subexponential quantum algorithms. In practice, this may lead to smaller parameters and more efficient schemes in certain cases.
In the second part of the talk, we illustrate this by diving deeper into MIKE itself, discuss how to compute the underlying action efficiently in practice, and present our promising implementation results. The first part of the talk is based on joint work with Emil August Hovd Olaisen, while the second part is with the whole "MIKE-team".
Next sessions
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Dissecting CRAFT, a full-round attack
Speaker : Eran Lambooij - Inria
I will present the first full-round key recovery attack on CRAFT, a block cipher introduced at ToSC 2019. The attack builds on the previous observation (ToSC 2026) that the state of CRAFT can be decomposed into two parts that barely exchange information. We transform this property into a dissection attack on the full-round cipher. This shows that in some cases we can elevate the dissection attack[…]-
Cryptography
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Key Attack on the ACDGV Matrix Encryption Scheme
Speaker : Anmoal Porwal - Technical University of Munich
I will present our key-recovery attack on the ACDGV public-key encryption scheme proposed at ASIACRYPT 2024 by Aragon, Couvreur, Dyseryn, Gaborit, and Vinçotte. The secret key is a Gabidulin code hidden by appending random rows and columns and by left- and right-multiplication with invertible matrices. Our attack exploits the resulting algebraic structure to recover an equivalent secret key. It[…]-
Cryptography
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Asymmetric primitive
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Module Learning With Errors and Structured Extrapolated Dihedral Cosets
Speaker : Jinwei Zheng - Télécom Paris
The Module Learning With Errors (MLWE) problem is the fundamental hardness assumption underlying the key encapsulation and signature schemes ML-KEM and ML-DSA, which have been selected by NIST for post-quantum cryptography standardization. Understanding its quantum hardness is crucial for assessing the security of these standardized schemes. Inspired by the equivalence between LWE and[…]-
Cryptography
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