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Publications associées (23)

On Quantum Secure Compressing Pseudorandom Functions

In this paper we characterize all 2n-bit-to-n-bit Pseudorandom Functions (PRFs) constructed with the minimum number of calls to n-bit-to-n-bit PRFs and arbitrary number of linear functions. First, we show that all two-round constructions are either classic ...

2023

Green Cryptography and Other Optimisations

Andrea Felice Caforio

The spectral decomposition of cryptography into its life-giving components yields an interlaced network of tangential and orthogonal disciplines that are nonetheless invariably grounded by the same denominator: their implementation on commodity computing p ...

EPFL2023

Bridging the gap between theoretical and practical privacy technologies for at-risk populations

Kasra Edalatnejadkhamene

With the pervasive digitalization of modern life, we benefit from efficient access to information and services. Yet, this digitalization poses severe privacy challenges, especially for special-needs individuals. Beyond being a fundamental human right, priv ...

EPFL2023

Secrecy by Design With Applications to Privacy and Compression

Yanina Yurina Shkel

Secrecy by design is examined as an approach to information-theoretic secrecy. The main idea behind this approach is to design an information processing system from the ground up to be perfectly secure with respect to an explicit secrecy constraint. The pr ...

2021

Time in cryptography

Gwangbae Choi

Time travel has always been a fascinating topic in literature and physics. In cryptography, one may wonder how to keep data confidential for some time. In this dissertation, we will study how to make private information travel to the future. This dissertat ...

EPFL2020

Timed-Release Encryption With Master Time Bound Key

Serge Vaudenay, Gwangbae Choi

Timed-release encryption allows senders to send a message to a receiver which cannot decrypt until a server releases a time bound key at the release time. The release time usually supposed to be known to the receiver, the ciphertext therefore cannot be dec ...

2019

Six Shades of AES

Subhadeep Banik, Muhammed Fatih Balli

Recently there have been various attempts to construct light weight implementations of the AES-128 encryption and combined encryption/ decryption circuits. However no known lightweight circuit exists forAES-192 and AES-256, the variants of AES that use lon ...

2019

Misuse Attacks on Post-quantum Cryptosystems

Serge Vaudenay, Loïs Evan Huguenin-Dumittan, Abdullah Talayhan, Fatma Betül Durak, Ciprian Baetu

Many post-quantum cryptosystems which have been proposed in the National Institute of Standards and Technology (NISI) standardization process follow the same meta-algorithm, but in different algebras or different encoding methods. They usually propose two ...

SPRINGER INTERNATIONAL PUBLISHING AG2019

Bidirectional Asynchronous Ratcheted Key Agreement with Linear Complexity

Serge Vaudenay, Fatma Betül Durak

Following up mass surveillance and privacy issues, modern secure communication protocols now seek more security such as forward secrecy and post-compromise security. They cannot rely on an assumption such as synchronization, predictable sender/receiver rol ...

Springer2019

Cryptanalysis of Enhanced MORE

Serge Vaudenay, Damian Vizár

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 ...

2018

Impact of score fusion on voice biometrics and presentation attack detection in cross-database evaluations

Sébastien Marcel

Research in the area of automatic speaker verification (ASV) has been advanced enough for the industry to start using ASV systems in practical applications. However, these systems are highly vulnerable to spoofing or presentation attacks, limiting their wi ...

2017

GIFT: A Small Present Towards Reaching the Limit of Lightweight Encryption

Subhadeep Banik

In this article, we revisit the design strategy of PRESENT, leveraging all the advances provided by the research community in construction and cryptanalysis since its publication, to push the design up to its limits. We obtain an improved version, named GI ...

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

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

Optimal Computational Split-state Non-malleable Codes

Divesh Aggarwal, Divya Gupta

Non-malleable codes are a generalization of classical error-correcting codes where the act of "corrupting" a codeword is replaced by a "tampering" adversary. Non-malleable codes guarantee that the message contained in the tampered codeword is either the or ...

Springer Int Publishing Ag2016

Building Security Protocols Against Powerful Adversaries

Iris Safaka

As our sensitive data is increasingly carried over the Internet and stored remotely, security in communications becomes a fundamental requirement. Yet, today's security practices are designed around assumptions the validity of which is being challenged. In ...

EPFL2016

Affine-malleable Extractors, Spectrum Doubling, and Application to Privacy Amplification

Divesh Aggarwal

The study of seeded randomness extractors is a major line of research in theoretical computer science. The goal is to construct deterministic algorithms which can take a weak random source x with min-entropy k and a uniformly random seed Y of length d, and ...

Ieee2016

Non-malleable Reductions and Applications

Divesh Aggarwal

Non-malleable codes, introduced by Dziembowski, Pietrzak and Wichs [DPW10], provide a useful message integrity guarantee in situations where traditional error-correction (and even error-detection) is impossible; for example, when the attacker can completel ...

ACM2015

Efficient Non-malleable Codes and Key-Derivation for Poly-size Tampering Circuits

Sebastian Faust

Non-malleable codes, defined by Dziembowski, Pietrzak and Wichs (ICS ’10), provide roughly the following guarantee: if a codeword c encoding some message x is tampered to c' = f(c) such that c c, then the tampered message x contained in c reveals no inf ...

Springer2014

Revisiting Iterated Attacks in the Context of Decorrelation Theory

Serge Vaudenay, Atefeh Mashatan, Asli Bay

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 perfect cipher C* based on all bits. Vaudenay showed that a 2d-dec ...

2014