Description
The McEliece scheme is a generic framework allowing to use any error correcting code which disposes of an efficient decoding algorithm to design an encryption scheme by hiding a generator matrix of this code.
In the context of rank metric, we propose a generalization of the McEliece frame to matrix codes. From a vector code, we compute a matrix version of this code, that is hidden in such a way that the code obtained is indistinguishable from a random code. We propose to mask the linearity of the vector code on the extension, which implies a bigger public key (since the code is less structured) but allows to allows to keep a very small size of ciphertext. It results in an encryption scheme whose security relies on a generic instance of the MinRank problem, known to be NP-complete.
Applying it with Gabidulin codes, our approach gives a better trade-off between ciphertexts and public keys sizes than the classic McEliece scheme. For 128 bits of security, we propose parameters with ciphertext of size 65B and public key of size 98kB.
Travail en commun avec Nicolas Aragon, Alain Couvreur, Victor Dyseryn, Philippe Gaborit
Infos pratiques
Prochains exposés
-
Wagner’s Algorithm Provably Runs in Subexponential Time for SIS^∞
Orateur : Johanna Loyer - Inria Saclay
At CRYPTO 2015, Kirchner and Fouque claimed that a carefully tuned variant of the Blum-Kalai-Wasserman (BKW) algorithm (JACM 2003) should solve the Learning with Errors problem (LWE) in slightly subexponential time for modulus q = poly(n) and narrow error distribution, when given enough LWE samples. Taking a modular view, one may regard BKW as a combination of Wagner’s algorithm (CRYPTO 2002), run[…]-
Cryptography
-
-
CryptoVerif: a computationally-sound security protocol verifier
Orateur : Bruno Blanchet - Inria
CryptoVerif is a security protocol verifier sound in the computational model of cryptography. It produces proofs by sequences of games, like those done manually by cryptographers. It has an automatic proof strategy and can also be guided by the user. It provides a generic method for specifying security assumptions on many cryptographic primitives, and can prove secrecy, authentication, and[…]-
Cryptography
-
-
Structured-Seed Local Pseudorandom Generators and their Applications
Orateur : Nikolas Melissaris - IRIF
We introduce structured‑seed local pseudorandom generators (SSL-PRGs), pseudorandom generators whose seed is drawn from an efficiently sampleable, structured distribution rather than uniformly. This seemingly modest relaxation turns out to capture many known applications of local PRGs, yet it can be realized from a broader family of hardness assumptions. Our main technical contribution is a[…]-
Cryptography
-
-
Predicting Module-Lattice Reduction
Orateur : Paola de Perthuis - CWI
Is module-lattice reduction better than unstructured lattice reduction? This question was highlighted as `Q8' in the Kyber NIST standardization submission (Avanzi et al., 2021), as potentially affecting the concrete security of Kyber and other module-lattice-based schemes. Foundational works on module-lattice reduction (Lee, Pellet-Mary, Stehlé, and Wallet, ASIACRYPT 2019; Mukherjee and Stephens[…]-
Cryptography
-