Publications associées à Remplissage (cryptographie)

Cryptographic Administration for Secure Group Messaging

Many real-world group messaging systems delegate group administration to the application level, failing to provide formal guarantees related to group membership. Taking a cryptographic approach to group administration can prevent both implementation and pr ...

Berkeley2023

Near Collision Attack Against Grain V1

Subhadeep Banik, Willi Meier, Daniel Patrick Collins

A near collision attack against the Grain v1 stream cipher was proposed by Zhang et al. in Eurocrypt 18. The attack uses the fact that two internal states of the stream cipher with very low hamming distance between them, produce similar keystream sequences ...

2023

Security in the Presence of Quantum Adversaries

Khashayar Barooti

With the looming threat of large-scale quantum computers, a fair portion of recent cryptographic research has focused on examining cryptographic primitives from the perspective of a quantum adversary. Shor's 1994 result revealed that quantum computers can ...

EPFL2023

Multiquadratic Rings and Walsh-Hadamard Transforms for Oblivious Linear Function Evaluation

Juan Ramón Troncoso-Pastoriza

The Ring Learning with Errors (RLWE) problem has become one of the most widely used cryptographic assumptions for the construction of modern cryptographic primitives. Most of these solutions make use of power-of-two cyclotomic rings mainly due to its simpl ...

IEEE2020

Cryptanalysis of LowMC instances using single plaintext/ciphertext pair

Serge Vaudenay, Subhadeep Banik, Fatma Betül Durak, Khashayar Barooti

Arguably one of the main applications of the LowMC family ciphers is in the post-quantum signature scheme PICNIC. Although LowMC family ciphers have been studied from a cryptanalytic point of view before, none of these studies were directly concerned with ...

2020

Reducing Metadata Leakage from Encrypted Files and Communication with PURBs

Jean-Pierre Hubaux, Bryan Alexander Ford, Ludovic Barman, Kirill Nikitin, Wouter Lueks, Matthew Joshua Underwood

Most encrypted data formats leak metadata via their plaintext headers, such as format version, encryption schemes used, number of recipients who can decrypt the data, and even the recipients’ identities. This leakage can pose security and privacy risks to ...

Sciendo2019

Arithmetic and geometric structures in cryptography

Benjamin Pierre Charles Wesolowski

We explore a few algebraic and geometric structures, through certain questions posed by modern cryptography. We focus on the cases of discrete logarithms in finite fields of small characteristic, the structure of isogeny graphs of ordinary abelian varietie ...

EPFL2018

PriFi: A Low-Latency and Tracking-Resistant Protocol for Local-Area Anonymous Communication

Jean-Pierre Hubaux, Ludovic Barman, Bryan Alexander Ford, Mahdi Zamani, Italo Ivan Dacosta Petrocelli

Popular anonymity mechanisms such as Tor provide low communication latency but are vulnerable to traffic analysis attacks that can de-anonymize users. Moreover, known traffic-analysis-resistant techniques such as Dissent are impractical for use in latency- ...

ACM2016

Efficient Ephemeral Elliptic Curve Cryptographic Keys

Arjen Lenstra, Andrea Miele

We show how any pair of authenticated users can on-the-fly agree on an elliptic curve group that is unique to their communication session, unpredictable to outside observers, and secure against known attacks. Our proposal is suitable for deployment on cons ...

Springer-Verlag Berlin2015

Algebraic Cryptanalysis of Deterministic Symmetric Encryption

Petr Susil

Deterministic symmetric encryption is widely used in many cryptographic applications. The security of deterministic block and stream ciphers is evaluated using cryptanalysis. Cryptanalysis is divided into two main categories: statistical cryptanalysis and ...

EPFL2015

On the Key Schedule of Lightweight Block Ciphers

Serge Vaudenay, Jialin Huang

Key schedules in lightweight block ciphers are often highly simplified, which causes weakness that can be exploited in many attacks. Today it remains an open problem on how to use limited operations to guarantee enough diffusion of key bits in lightweight ...

Springer-Verlag Berlin2014

On Hiding a Plaintext Length by Preencryption

Serge Vaudenay, Cihangir Tezcan

It is a well known fact that encryption schemes can not hide a plaintext length when it is unbounded. We thus admit that an approximation of it may leak and we focus on hiding its precise value. Some standards such as TLS or SSH offer to do it by applying ...

Springer2011

Practical unconditionally secure two-channel message authentication

Atefeh Mashatan

We investigate unconditional security for message authentication protocols that are designed using two-channel cryptography. (Two-channel cryptography employs a broadband, insecure wireless channel and an authenticated, narrow-band manual channel at the sa ...

2010

An Analysis of the Blockcipher-Based Hash Functions from PGV

Martijn Stam

Preneel, Govaerts, and Vandewalle (1993) considered the 64 most basic ways to construct a hash function H: {0, 1}*->{0, 1}(n) from a blockcipher E: {0, 1}(n) x {0, 1}(n)->{0,1}(n). They regarded 12 of these 64 schemes as secure, though no proofs or formal ...

Springer Verlag2010

Cryptographic protocol logic: Satisfaction for (timed) Dolev-Yao cryptography

Simon Kramer

This article is about a breadth-first exploration of logical concepts in cryptography and their linguistic abstraction and model-theoretic combination in a comprehensive logical system, called CPL (for Cryptographic Protocol Logic). We focus on two fundame ...

2008

Logical concepts in cryptography

Simon Kramer

This thesis is about a breadth-first exploration of logical concepts in cryptography and their linguistic abstraction and model-theoretic combination in a comprehensive logical system, called CPL (for Cryptographic Protocol Logic). We focus on two fundamen ...

EPFL2007

Efficient secure aggregation in VANETs

Jean-Pierre Hubaux, Adel Aziz, Maxime Raya

In VANETs, better communication efficiency can be achieved by sacrificing security and vice versa. But VANETs cannot get started without either of them. In this paper, we propose a set of mechanisms that can actually reconcile these two contradictory requi ...

2006