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Concept

Confidentialité persistante

Publications associées (31)

On the Theory and Practice of Modern Secure Messaging

Daniel Patrick Collins

Billions of people now have conversations daily over the Internet. A large portion of this communication takes place via secure messaging protocols that offer "end-to-end encryption'" guarantees and resilience to compromise like the widely-used Double Ratc ...

EPFL2024

PAE: Towards More Efficient and BBB-Secure AE from a Single Public Permutation

Ritam Bhaumik

Four recent trends have emerged in the evolution of authenticated encryption schemes: (1) Regarding simplicity, the adoption of public permutations as primitives allows for sparing a key schedule and the need for storing round keys; (2) using the sums of p ...

Springer2023

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

A semi-supervised algorithm for improving the consistency of crowdsourced datasets: The COVID-19 case study on respiratory disorder classification

David Atienza Alonso, Tomas Teijeiro Campo, Lara Orlandic

Background and Objective: Cough audio signal classification is a potentially useful tool in screening for respiratory disorders, such as COVID-19. Since it is dangerous to collect data from patients with contagious diseases, many research teams have turned ...

2023

Moby: A Blackout-Resistant Anonymity Network for Mobile Devices

Bryan Alexander Ford, Antoine Rault

Internet blackouts are challenging environments for anonymity and censorship resistance. Existing popular anonymity networks (e.g., Freenet, I2P, Tor) rely on Internet connectivity to function, making them impracticable during such blackouts. In such a set ...

2022

Analysis and Improvements of the Sender Keys Protocol for Group Messaging

Daniel Patrick Collins

Messaging between two parties and in the group setting has enjoyed widespread attention both in practice, and, more recently, from the cryptographic community. One of the main challenges in the area is constructing secure (end-to- end encrypted) and effici ...

2022

Symmetry in design and decoding of polar-like codes

Kirill Ivanov

The beginning of 21st century provided us with many answers about how to reach the channel capacity. Polarization and spatial coupling are two techniques for achieving the capacity of binary memoryless symmetric channels under low-complexity decoding algor ...

EPFL2022

Beyond Security and Efficiency: On-Demand Ratcheting with Security Awareness

Serge Vaudenay, Andrea Felice Caforio, Fatma Betül Durak

Secure asynchronous two-party communication applies ratcheting to strengthen privacy, in the presence of internal state exposures. Security with ratcheting is provided in two forms: forward security and post-compromise security. There have been several suc ...

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

Symmetric Asynchronous Ratcheted Communication with Associated Data

Serge Vaudenay, Hailun Yan

Following up mass surveillance and privacy issues, modern secure communication protocols now seek strong security, such as forward secrecy and post-compromise security, in the face of state exposures. To address this problem, ratcheting was thereby introdu ...

Springer, Cham2020

Determining the Core Primitive for Optimally Secure Ratcheting

Serge Vaudenay, Muhammed Fatih Balli

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 ...

2020

Are Cloud FPGAs Really Vulnerable to Power Analysis Attacks?

Francesco Regazzoni, Mirjana Stojilovic, Ognjen Glamocanin, Louis Coulon

Recent works have demonstrated the possibility of extracting secrets from a cryptographic core running on an FPGA by means of remote power analysis attacks. To mount these attacks, an adversary implements a voltage fluctuation sensor in the FPGA logic, rec ...

IEEE2020

Key Negotiation Downgrade Attacks on Bluetooth and Bluetooth Low Energy

Daniele Antonioli

Bluetooth (BR/EDR) and Bluetooth Low Energy (BLE) are pervasive wireless technologies specified in the Bluetooth standard. The standard includes key negotiation protocols used to generate long-term keys (during pairing) and session keys (during secure conn ...

ASSOC COMPUTING MACHINERY2020

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

Compact Circuits for Combined AES Encryption/Decryption

Subhadeep Banik

The implementation of the AES encryption core by Moradi et al. at Eurocrypt 2011 is one of the smallest in terms of gate area. The circuit takes around 2400 gates and operates on an 8 bit datapath. However this is an encryption only core and unable to cate ...

2019

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

SUNDAE: Small Universal Deterministic Authenticated Encryption for the Internet of Things

Subhadeep Banik

Lightweight cryptography was developed in response to the increasing need to secure devices for the Internet of Things. After significant research effort, many new block ciphers have been designed targeting lightweight settings, optimizing efficiency metri ...

2018

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

Generating Steganographic Text with LSTMs

Martin Jaggi, Aikaterini Argyraki

Motivated by concerns for user privacy, we design a steganographic system ("stegosystem") that enables two users to exchange encrypted messages without an adversary detecting that such an exchange is taking place. We propose a new linguistic stegosystem ba ...

2017

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