143 research outputs found
Encryption with Quantum Public Keys
It is an important question to find constructions of quantum cryptographic
protocols which rely on weaker computational assumptions than classical
protocols. Recently, it has been shown that oblivious transfer and multi-party
computation can be constructed from one-way functions, whereas this is
impossible in the classical setting in a black-box way. In this work, we study
the question of building quantum public-key encryption schemes from one-way
functions and even weaker assumptions. Firstly, we revisit the definition of
IND-CPA security to this setting. Then, we propose three schemes for quantum
public-key encryption from one-way functions, pseudorandom function-like states
with proof of deletion and pseudorandom function-like states, respectively.Comment: This paper is subsumed and superseded by arXiv:2303.0208
Une approche par invariants de la fatigue multiaxiale sous chargement complexe : prédiction de la durée de vie
Un critère de fatigue multiaxiale à grand
nombre de cycles est construit sur des invariants du tenseur des contraintes
macroscopique. La présence de J2,moy permet de refléter correctement l'effet de la phase
sur la limite de fatigue d'un matériau. L'étude réalisée sur 119 essais valide la
capacité de prédiction du critère. Un modèle d'endommagement intégrant ce critère est
présenté, permettant de simuler la durée de vie dans le domaine de l’endurance limitée
(100000 – 1 million cycles). Le modèle est identifié et validé à partir d’observations
expérimentales réalisées sur un acier C35
Unclonable Cryptography in the Plain Model
By leveraging the no-cloning principle of quantum mechanics, unclonable cryptography enables us to achieve novel cryptographic protocols that are otherwise impossible classically. Two most notable examples of unclonable cryptography are quantum copy-protection and unclonable encryption. Despite receiving a lot of attention in recent years, two important open questions still remain: copy- protection for point functions in the plain model, which is usually considered as feasibility demonstration, and unclonable encryption with unclonable indistinguishability security in the plain model.
In this work, by relying on previous works of Coladangelo, Liu, Liu, and Zhandry (Crypto’21) and Culf and Vidick (Quantum’22), we establish a new monogamy-of-entanglement property for subspace coset states, which allows us to obtain the following new results:
• We show that copy-protection of point functions exists in the plain model, with different challenge distributions (including arguably the most natural ones).
• We show, for the first time, that unclonable encryption with unclonable indistinguishability security exists in the plain model
Semi-Quantum Copy-Protection and More
Properties of quantum mechanics have enabled the emergence of quantum cryptographic protocols achieving important goals which are proven to be impossible classically. Unfortunately, this usually comes at the cost of needing quantum power from every party in the protocol, while arguably a more realistic scenario would be a network of classical clients, classically interacting with a quantum server.
In this paper, we focus on copy-protection, which is a quantum primitive that allows a program to be evaluated, but not copied, and has shown interest especially due to its links to other unclonable cryptographic primitives. Our main contribution is to show how to dequantize existing quantum copy-protection from hidden coset states, by giving a construction for classically-instructed remote state preparation for coset states. We then apply this dequantizer to obtain semi-quantum cryptographic protocols for copy-protection and tokenized signatures with strong unforgeability. In the process, we present the first secure copy-protection scheme for point functions in the plain model and a new direct product hardness property of coset states which immediately implies a strongly unforgeable tokenized signature scheme
Post-Quantum UC-Secure Oblivious Transfer in the Standard Model with Adaptive Corruptions
Since the seminal result of Kilian, Oblivious Transfer has proven to be a
fundamental primitive in cryptography. In such a scheme, a user is able
to gain access to an element owned by a server, without learning more than
this single element, and without the server learning which element the user
has accessed. This primitive has received a lot of study in the literature,
among which very few schemes are based on lattices.
The recent NIST call for post-quantum encryption and signature
schemes has revived the interest for cryptographic protocols based on
post-quantum assumptions and the need for a secure post-quantum
oblivious transfer scheme.
In this paper, we show how to construct an oblivious transfer
scheme based on lattices, from a collision-resistant chameleon hash
scheme (CH) and a CCA encryption scheme accepting a smooth projective
hash function (SPHF). Note that our scheme does not rely on random
oracles and provides UC security against adaptive corruptions assuming
reliable erasures
A new semislug of the genus Laocaia (Gastropoda, Pulmonata, Helicarionidae) from Vietnam
A new species of the genus Laocaia Kuzminykh, 1999, Laocaia simovi Dedov & Schneppat, sp. nov., is described, which was collected from a single locality in northern Vietnam. Color pictures of living specimens are provided. For the first time, information on the ecology and biology of a representative of the genus Laocaia is presented
Encryption with Quantum Public Keys
It is an important question to find constructions of quantum cryptographic protocols which rely on weaker computational assumptions than classical protocols. Recently, it has been shown that oblivious transfer and multi-party computation can be constructed from one-way functions, whereas this is impossible in the classical setting in a black-box way. In this work, we study the question of building quantum public-key encryption schemes from one-way functions and even weaker assumptions. Firstly, we revisit the definition of IND-CPA security to this setting. Then, we propose three schemes for quantum public-key encryption from one-way functions, pseudorandom function-like states with proof of deletion and pseudorandom function-like states, respectively
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