Personne

Serge Vaudenay

Publications associées (152)

Generic Round-Function-Recovery Attacks for Feistel Networks over Small Domains

Feistel Networks (FN) are now being used massively to encrypt credit card numbers through format-preserving encryption. In our work, we focus on FN with two branches, entirely unknown round functions, modular additions (or other group operations), and when ...

2018

Contactless Access Control Based on Distance Bounding

Serge Vaudenay

Contactless access control systems are critical for security but often vulnerable to relay attacks. In this paper, we define an integrated security and privacy model for access control using distance bounding (DB) which is the most robust solution to preve ...

2017

Method and apparatus for wireless validation

Serge Vaudenay, Handan Kilinç Alper

A wireless validation method between an first apparatus and a second apparatus comprising the following steps of communicating between the first apparatus and the second apparatus for agreeing in a protected way on a common symmetric key and performing a s ...

2017

Breaking the FF3 Format Preserving Encryption

Serge Vaudenay, Fatma Betül Durak

The NIST standard FF3 scheme (also known as BPS scheme) is a tweakable block cipher based on a 8-round Feistel Network. We break it with a practical attack. Our attack exploits the bad domain separation in FF3 design. The attack works with chosen plaintext ...

2017

Breaking The FF3 Format-Preserving Encryption Standard Over Small Domains

Serge Vaudenay, Fatma Betül Durak

The National Institute of Standards and Technology (NIST) recently published a Format-Preserving Encryption standard accepting two Feistel structure based schemes called FF1 and FF3. Particularly, FF3 is a tweakable block cipher based on an 8-round Feistel ...

2017

On Selection of Samples in Algebraic Attacks and a New Technique to Find Hidden Low Degree Equations

Serge Vaudenay, Pouyan Sepehrdad, Petr Susil

The best way of selecting samples in algebraic attacks against block ciphers is not well explored and understood. We introduce a simple strategy for selecting the plaintexts and demonstrate its strength by breaking reduced-round KATAN, LBLOCK and SIMON. Fo ...

Springer Verlag2016

Circular Security Reconsidered

Serge Vaudenay, Fatma Betül Durak

The notion of circular security of pseudorandom functions (PRF) was introduced in Distance Bounding Protocols. So far, only a construction based on a random oracle model was proposed. Circular security stands between two new notions which we call Key Depen ...

Springer International Publishing2016

Privacy failure in the public-key distance-bounding protocols

Serge Vaudenay

Public-key distance bounding protocols are well suited to defeat relay attacks in proximity access control systems when the author assume no prior shared key. At AsiaCCS 2014, Gambs, Onete, and Robert designed such a protocol with privacy protection for th ...

Inst Engineering Technology-Iet2016

Optimization of LPN Solving Algorithms

Serge Vaudenay, Sonia Mihaela Bogos

In this article we focus on constructing an algorithm that automatizes the generation of LPN solving algorithms from the considered parameters. When searching for an algorithm to solve an LPN instance, we make use of the existing techniques and optimize th ...

Springer-Verlag Berlin2016

DES S-box generator

Serge Vaudenay, Lauren De Meyer

The Data Encryption Standard (DES) is a cryptographic algorithm, designed by IBM, that was selected to be the national standard in 1977 by the National Bureau of Standards. The algorithm itself was entirely published but the design criteria were kept secre ...

Taylor & Francis Inc2016

On solving LPN using BKW and variants Implementation and Analysis

Serge Vaudenay, Florian Tramèr, Sonia Mihaela Bogos

The Learning Parity with Noise problem (LPN) is appealing in cryptography as it is considered to remain hard in the post-quantum world. It is also a good candidate for lightweight devices due to its simplicity. In this paper we provide a comprehensive anal ...

Springer2016

When Constant-time Source Yields Variable-time Binary: Exploiting Curve25519-donna Built with MSVC 2015

Serge Vaudenay

The elliptic curve Curve25519 has been presented as pro- tected against state-of-the-art timing attacks [2]. This paper shows that a timing attack is still achievable against a particular X25519 implemen- tation which follows the RFC 7748 requirements [11] ...

Springer Int Publishing Ag2016

Side-Channel Attacks on Threshold Implementations using a Glitch Algebra

Serge Vaudenay

Threshold implementations allow to implement circuits us- ing secret sharing in a way to thwart side-channel attacks based on prob- ing or power analysis. It was proven they resist to attacks based on glitches as well. In this report, we show the limitatio ...

Springer Int Publishing Ag2016

Distance Bounding based on PUF

Serge Vaudenay, Mathilde Igier

Distance Bounding (DB) is designed to mitigate relay attacks. This paper provides a complete study of the DB protocol of Kleber et al. based on Physical Unclonable Functions (PUFs). We contradict the claim that it resists to Terrorist Fraud (TF). We propos ...

Springer Int Publishing Ag2016

Cryptanalysis of a Homomorphic Encryption Scheme

Serge Vaudenay, Sonia Mihaela Bogos, John Gaspoz

Homomorphic encryption allows to make specific operations on private data which stays encrypted. While applications such as cloud computing require to have a practical solution, the encryption scheme must be secure. In this article, we detail and analyze i ...

2016

Authenticated Encryption with Variable Stretch

Serge Vaudenay, Reza Reyhanitabar, Damian Vizár

In conventional authenticated-encryption (AE) schemes, the ciphertext expansion, a.k.a.stretch or tag length, is a constant or a parameter of the scheme that must be fixed per key. However, using variable-length tags per key can be desirable in practice or ...

Springer-Verlag Berlin2016

Efficient Public-Key Distance Bounding Protocol

Serge Vaudenay, Handan Kilinç Alper

Distance bounding protocols become more and more important because they are the most accurate solution to defeat relay attacks. They consist of two parties: a verifier and a prover. The prover shows that (s)he is close enough to the verifier. In some appli ...

Springer-Verlag Berlin2016

The Limits of Composable Crypto with Transferable Setup Devices

Serge Vaudenay, Miyako Ohkubo

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 ...

ACM2015

Better Algorithms for LWE and LWR

Serge Vaudenay, Alexandre Raphaël Duc, Florian Tramèr

The Learning With Error problem (LWE) is becoming more and more used in cryptography, for instance, in the design of some fully homomorphic encryption schemes. It is thus of primordial importance to find the best algorithms that might solve this problem so ...

Springer2015

How to Sequentialize Independent Parallel Attacks? - Biased Distributions Have a Phase Transition

Serge Vaudenay, Sonia Mihaela Bogos

We assume a scenario where an attacker can mount several independent attacks on a single CPU. Each attack can be run several times in independent ways. Each attack can succeed after a given number of steps with some given and known probability. A natural q ...

2015