Publications associées à Fonction de compression

Secure and Efficient Cryptographic Algorithms in a Quantum World

Since the advent of internet and mass communication, two public-key cryptographic algorithms have shared the monopoly of data encryption and authentication: Diffie-Hellman and RSA. However, in the last few years, progress made in quantum physics -- and mo ...

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

A Gapless Post-quantum Hash Proof System in the Hamming Metric

Serge Vaudenay, Bénédikt Minh Dang Tran

A hash proof system (HPS) is a form of implicit proof of membership to a language. Out of the very few existing post-quantum HPS, most are based on languages of ciphertexts of code-based or lattice-based cryptosystems and inherently suffer from a gap cause ...

2023

On Succinct Non-interactive Arguments in Relativized Worlds

Alessandro Chiesa

Succinct non-interactive arguments of knowledge (SNARKs) are cryptographic proofs with strong efficiency properties. Applications of SNARKs often involve proving computations that include the SNARK verifier, a technique called recursive composition. Unfort ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

Zero-Knowledge IOPs with Linear-Time Prover and Polylogarithmic-Time Verifier

Alessandro Chiesa, Siqi Liu

Interactive oracle proofs (IOPs) are a multi-round generalization of probabilistically checkable proofs that play a fundamental role in the construction of efficient cryptographic proofs. ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

Analyzing and Protecting Communication Metadata

Ludovic Barman

Most communication systems (e.g., e-mails, instant messengers, VPNs) use encryption to prevent third parties from learning sensitive information. However, encrypted communications protect the contents but often leak metadata: the amount of data sent and th ...

EPFL2021

Serial Lightweight Implementation Techniques for Block Ciphers

Muhammed Fatih Balli

Most of the cryptographic protocols that we use frequently on the internet are designed in a fashion that they are not necessarily suitable to run in constrained environments. Applications that run on limited-battery, with low computational power, or area ...

EPFL2021

Energy Analysis of Lightweight AEAD Circuits

Subhadeep Banik, Muhammed Fatih Balli, Andrea Felice Caforio

The selection criteria for NIST's Lightweight Crypto Standardization (LWC) have been slowly shifting towards the lightweight efficiency of designs, given that a large number of candidates already establish their security claims on conservative, well-studie ...

2020

Cryptanalysis of ForkAES

Subhadeep Banik, Willi Meier

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

Beyond Conventional Security in Sponge-Based Authenticated Encryption Modes

Philipp Svetolik Jovanovic

The Sponge function is known to achieve 2c/2 security, where c is its capacity. This bound was carried over to its keyed variants, such as SpongeWrap, to achieve a min{2c/2,2 kappa} security bound, with kappa the key length. Similarly, many CAESAR competit ...

SPRINGER2019

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

A Lyra2 FPGA Core for Lyra2REv2-Based Cryptocurrencies

Alexios Konstantinos Balatsoukas Stimming, Pascal Giard, Michiel Van Beirendonck

Lyra2REv2 is a hashing algorithm that consists of a chain of individual hashing algorithms and it is used as a proof-of-work function in several cryptocurrencies that aim to be ASIC-resistant. The most crucial hashing algorithm in the Lyra2REv2 chain is a ...

IEEE2019

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

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

Logistic regression over encrypted data from fully homomorphic encryption

Zhicong Huang

Background: One of the tasks in the 2017 iDASH secure genome analysis competition was to enable training of logistic regression models over encrypted genomic data. More precisely, given a list of approximately 1500 patient records, each with 18 binary feat ...

2018

Towards Low Energy Stream Ciphers

Francesco Regazzoni, Subhadeep Banik, Willi Meier

Energy optimization is an important design aspect of lightweight cryptography. Since low energy ciphers drain less battery, they are invaluable components of devices that operate on a tight energy budget such as handheld devices or RFID tags. At Asiacrypt ...

2018

Security of Full-State Keyed Sponge and Duplex: Applications to Authenticated Encryption

Damian Vizár, Reza Reyhanitabar

We provide a security analysis for full-state keyed Sponge and full-state Duplex constructions. Our results can be used for making a large class of Sponge-based authenticated encryption schemes more efficient by concurrent absorption of associated data and ...

Springer2015

Boosting OMD for Almost Free Authentication of Associated Data

Serge Vaudenay, Damian Vizár, Reza Reyhanitabar

We propose pure OMD (p-OMD) as a new variant of the Offset Merkle-Damgård (OMD) authenticated encryption scheme. Our new scheme inherits all desirable security features of OMD while having a more compact structure and providing higher efficiency. The origi ...

Springer2015

Efficient Recursive Diffusion Layers for Block Ciphers, and Hash Functions

Pouyan Sepehrdad

Many modern block ciphers use maximum distance separable (MDS) matrices as the main part of their diffusion layers. In this paper, we propose a very efficient new class of diffusion layers constructed from several rounds of Feistel-like structures whose ro ...

Springer2015

Protecting against Multidimensional Linear and Truncated Differential Cryptanalysis by Decorrelation

Serge Vaudenay

The decorrelation theory provides a different point of view on the security of block cipher primitives. Results on some statistical attacks obtained in this context can support or provide new insight on the security of symmetric cryptographic primitives. I ...

Springer-Verlag Berlin2015