Description
In this work, we apply the rebound attack to the AES based SHA-3 candidate LANE. The hash function LANE uses a permutation based compression function, consisting of a linear message expansion and 6 parallel lanes. In the rebound attack on LANE, we apply several new techniques to construct a collision for the full compression function of LANE-256 and LANE-512. Using a relatively sparse truncated differential path, we are able to solve for a valid message expansion and colliding lanes independently. Additionally, we are able to apply the inbound phase more than once by exploiting the degrees of freedom in the parallel AES states. This allows us to construct semi-free-start collisions for full LANE-256 with $2^{96}$ compression function evaluations and $2^{88}$ memory, and for full LANE-512 with $2^{224}$ compression function evaluations and $2^{128}$ memory. This is a joint work with K. Matusiewicz, I. Nikolic, Y. Sasaki and M. Schläffer.
Prochains exposés
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Algorithms for post-quantum commutative group actions
Orateur : Marc Houben - Inria Bordeaux
At the historical foundation of isogeny-based cryptography lies a scheme known as CRS; a key exchange protocol based on class group actions on elliptic curves. Along with more efficient variants, such as CSIDH, this framework has emerged as a powerful building block for the construction of advanced post-quantum cryptographic primitives. Unfortunately, all protocols in this line of work are[…] -
Endomorphisms via Splittings
Orateur : Min-Yi Shen - No Affiliation
One of the fundamental hardness assumptions underlying isogeny-based cryptography is the problem of finding a non-trivial endomorphism of a given supersingular elliptic curve. In this talk, we show that the problem is related to the problem of finding a splitting of a principally polarised superspecial abelian surface. In particular, we provide formal security reductions and a proof-of-concept[…]-
Cryptography
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