Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Chosen-ciphertext attack

Publications associées (26)

Attacks on some post-quantum cryptographic protocols: The case of the Legendre PRF and SIKE

Novak Kaluderovic

Post-quantum cryptography is a branch of cryptography which deals with cryptographic algorithms whose hardness assumptions are not based on problems known to be solvable by a quantum computer, such as the RSA problem, factoring or discrete logarithms. This ...

EPFL2022

Analysis of the BIKE post-quantum cryptographic protocols and the Legendre pseudorandom function

Dusan Kostic

The field of post-quantum cryptography studies cryptographic systems that are secure against an adversary in possession of a quantum computer. In 2017, the National Institute of Standards and Technology (NIST) initiated a process to standardize quantum-res ...

EPFL2020

Misuse Attacks on Post-quantum Cryptosystems

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

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

Cryptanalysis of ForkAES

Subhadeep Banik

Forkciphers are a new kind of primitive proposed recently by Andreeva et al. for efficient encryption and authentication of small messages. They fork the middle state of a cipher and encrypt it twice under two smaller independent permutations. Thus, forkci ...

2019

Can Caesar Beat Galois?

Serge Vaudenay, Damian Vizár

The Competition for Authenticated Encryption: Security, Applicability and Robustness (CAESAR) has as its official goal to “identify a portfolio of authenticated ciphers that offer advantages over [the Galois-Counter Mode with AES]” and are suitable for wid ...

2018

Provably Secure Authenticated Encryption

Damian Vizár

Authenticated Encryption (AE) is a symmetric key cryptographic primitive that ensures confidentiality and authenticity of processed messages at the same time. The research of AE as a primitive in its own right started in 2000. The security goals of AE wer ...

EPFL2018

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

Multicloud Resource Allocation : Cooperation, Optimization and Sharing

Hao Zhuang

Nowadays our daily life is not only powered by water, electricity, gas and telephony but by "cloud" as well. Big cloud vendors such as Amazon, Microsoft and Google have built large-scale centralized data centers to achieve economies of scale, on-demand res ...

EPFL2017

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

Experimental Comparison of Multicast Authentication for Wide Area Monitoring Systems

Jean-Yves Le Boudec, Teklemariam Tsegay Tesfay

Multicast is proposed as a preferred communication mechanism for many power grid applications. One of the biggest challenges for multicast in smart grid is ensuring source authentication without violating the stringent time requirement. The research commun ...

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

Optimizing Information Leakage in Multicloud Storage Services

Karl Aberer, Rameez Rahman, Hao Zhuang

Many schemes have been recently advanced for storing data on multiple clouds. Distributing data over multiple cloud storage providers automatically provides users with a certain degree of information leakage control, for no single point of attack can leak ...

2016

Signature Schemes Secure Against Hard-to-Invert Leakage

Sebastian Faust

Side-channel attacks allow the adversary to gain partial knowledge of the secret key when cryptographic protocols are implemented in real-world hardware. The goal of leakage resilient cryptography is to design cryptosystems that withstand such attacks. In ...

Springer2016

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

Serge Vaudenay, Pouyan Sepehrdad, Petr Susil

Springer-Verlag Berlin2014

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

Unifying Leakage Models: From Probing Attacks to Noisy Leakage

Alexandre Raphaël Duc, Sebastian Faust

A recent trend in cryptography is to formally show the leakage resilience of cryptographic implementations in a given leakage model. One of the most prominent leakage models -- the so-called bounded leakage model -- assumes that the amount of leakage is a- ...

Springer2014

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

HELEN: A Public-Key Cryptosystem Based on the LPN and the Decisional Minimal Distance Problems

Serge Vaudenay, Alexandre Raphaël Duc

We propose HELEN, a code-based public-key cryptosystem whose security is based on the hardness of the Learning from Parity with Noise problem (LPN) and the decisional minimum distance problem. We show that the resulting cryptosystem achieves indistinguisha ...

Springer2013

Bounded Tamper Resilience: How to go beyond the Algebraic Barrier

Sebastian Faust

Related key attacks (RKAs) are powerful cryptanalytic attacks where an adversary can change the secret key and observe the effect of such changes at the output. The state of the art in RKA security protects against an a-priori unbounded number of certain a ...

2013

Asynchronous Gossip

Rachid Guerraoui, Seth Gilbert

We study the complexity of gossip in an asynchronous, message-passing fault-prone distributed system. We show that an adaptive adversary can significantly hamper the spreading of a rumor, while an oblivious adversary cannot. The algorithmic techniques prop ...

Association for Computing Machinery2013