Publications de Serge Vaudenay

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.

Fully homomorphic encryption (FHE) has been among the most popular research topics of the last decade. While the bootstrapping-based, public key cryptosystems that follow Gentry's original design are getting more and more efficient, their performance is st ...

After ratcheting attracted attention mostly due to practical real-world protocols, recently a line of work studied ratcheting as a primitive from a theoretic point of view. Literature in this line, pursuing the strongest security of ratcheting one can hope ...

Decorrelation theory has recently been proposed in order to address the security of block ciphers and other cryptographic primitives over a finite domain. We show here how to extend it to infinite domains, which can be used in the Message Authentication Code (MAC) case. In 1994, Bellare, Kilian and Rogaway proved that CBC-MAC is secure when the input length is fixed. This has been extended by Petrank and Rackoff in 1997 with a variable length. In this paper, we prove a result similar to Petrank and Rackoff'

We look at the problem of designing Message Recognition Protocols (MRP) and note that all proposals available in the literature have relied on security proofs which hold in the random oracle model or are based on non-standard assumptions. Incorporating ran ...

Recently, we showed how to strengthen block ciphers by decorrelation techniques. In particular, we proposed two practical block ciphers, one based on the GF(2n)-arithmetics, the other based on the x mod p mod 2n primitive with a prime p=2n(1+d). We show how to achieve similar decorrelation with a prime p=2n(1-d). For this we have to change the choice of the norm in the decorrelation theory and replace the L8 norm by the L2 norm. We propose a

Digital signatures are often proven to be secure in the random oracle model while hash functions deviate more and more from this idealization. Liskov proposed to model a weak hash function by a random oracle together with another oracle allowing to break s ...

This paper is devoted to the design and analysis of short undeniable signatures based on a random oracle. Exploiting their online property, we can achieve signatures with a fully scalable size depending on the security level. To this end, we develop a gene ...

UC security realized with setup devices imposes that single instances of these setups are used. In most cases, UC-realization relies further on other properties of the setups devices, like tamper-resistance. But what happens in stronger versions of the UC ...

In self-encryption, a device encrypts some piece of information for itself to decrypt in the future. We are interested in security of self-encryption when the state occasionally leaks. Applications that use self-encryption include cloud storage, when a cli ...

The concept of Match-on-Card (MoC) consists of a smart card which receives an applicant's candidate template T to be compared with the stored reference template T_ref by processing the complete matching algorithm during a biometric authentication request. ...

Iterated attacks are comprised of iterating adversaries who can make

d

plaintext queries, in each iteration to compute a bit, and are trying to distinguish between a random cipher

C

and the ideal random cipher

C^*

based on all bits. In EUROCRYPT '99, ...

Decorrelation theory has recently been proposed in order to address the security of block ciphers and other cryptographic primitives over a finite domain. We show here how to extend it to infinite domains, which can be used in the message authentication code (MAC) case. Bellare et al., (1994), proved that CBC-MAC is secure when the input length is fixed. This has been extended by Petrank and Rackoff (1997) with a variable length. We prove a result similar to Petrank and Rackoff's one by using decorrelation

The communication between an honest prover and an honest verifier can be intercepted by a malicious man-in-the-middle (MiM), without the legitimate interlocutors noticing the intrusion. The attacker can simply relay messages from one party to another, even ...

This paper improves the Finiasz-Vaudenay construction of TCHo, a hardware-oriented public-key cryptosystem, whose security relies in the hardness of finding a low-weight multiple of a given polynomial, and on the decoding of certain noisy cyclic linear cod ...

We introduce a new computational problem related to the interpolation of group homomorphisms which generalizes many famous cryptographic problems including discrete logarithm, Diffie-Hellman, and RSA. As an application, we propose a generic undeniable signature scheme which generalizes the MOVA schemes. Our scheme is generic in the sense that we transform a private group homomorphism from public groups G to H (the order of H being public) into an undeniable signature scheme. It is provably secure in the ran

A dynamic universal accumulator is an accumulator that allows one to efficiently compute both membership and nonmembership witnesses in a dynamic way. It was first defined and instantiated by Li et al., based on the Strong RSA problem, building on the dynamic accumulator of Camenisch and Lysyanskaya. We revisit their construction and show that it does not provide efficient witness computation in certain cases and, thus, is only achieving the status of a partially dynamic universal accumulator. In particular

Since Gentry’s breakthrough result was introduced in the year 2009, the homomorphic encryption has become a very popular topic. The main contribution of Gentry’s thesis was, that it has proven, that it actually is possible to design a fully homomorphic enc ...

At ACM~CCS 2008, Rasmussen and Capkun introduced a distance-bounding protocol RC07 (henceforth RC protocol) where the prover and verifier use simultaneous transmissions and the verifier counts the delay between sending a challenge (starting with a hidden marker) and receiving the response. Thus, the verifier is able to compute an upper bound on the distance separating it and the prover. Distance bounding protocols should resist to the most classical types of attacks such as distance fraud and mafia fraud. I

In this paper we study the substitution-permutation network (SPN) on which Rijndael is based. We introduce Rijndael*, a SPN identical to Rijndael except that fixed S-boxes are replaced by random and independent permutations. We prove that this construction ...

Serge Vaudenay

Chattez avec Graph Search

Cryptanalysis of Enhanced MORE

Determining the Core Primitive for Optimally Secure Ratcheting

Decorrelation over Infinite Domains: the Encrypted CBC-MAC Case

A Message Recognition Protocol Based on Standard Assumptions

Decorrelation over Infinite Domains: the Encrypted CBC-MAC Case

Feistel ciphers with L2-decorrelation

Hash-and-Sign with Weak Hashing Made Secure

Short Undeniable Signatures Based on Group Homomorphisms

The Limits of Composable Crypto with Transferable Setup Devices

Post-Compromise Security in Self-Encryption

A Protection Scheme for MoC-Enabled Smart Cards

Resistance Against Iterated Attacks by Decorrelation Revisited

Decorrelation over infinite domains: the encrypted CBC-MAC case

The Bussard-Bagga and Other Distance-Bounding Protocols under Attacks

TCHo: a Hardware-Oriented Trapdoor Cipher

Generic homomorphic undeniable signatures

A Fully Dynamic Universal Accumulator

Cryptanalysis of Chosen Symmetric Homomorphic Schemes

Mafia Fraud Attack against the RC Distance-Bounding Protocol

Proving the Security of AES Substitution-Permutation Network