Publications associées à Réseau de substitution-permutation

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

BBB security for 5-round even-Mansour-based key-alternating Feistel ciphers

Ritam Bhaumik

In this paper, we study the security of the Key-Alternating Feistel (KAF) ciphers, a class of key alternating ciphers with the Feistel structure, where each round of the cipher is instantiated with n-bit public round permutation Pi\documentclass[12pt]{mini ...

SPRINGER2023

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

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

Efficient Bootstrapping for Approximate Homomorphic Encryption with Non-sparse Keys

Jean-Pierre Hubaux, Juan Ramón Troncoso-Pastoriza, Jean-Philippe Léonard Bossuat, Christian Vincent Mouchet

We present a bootstrapping procedure for the full-RNS variant of the approximate homomorphic-encryption scheme of Cheon et al., CKKS (Asiacrypt 17, SAC 18). Compared to the previously proposed procedures (Eurocrypt 18 & 19, CT-RSA 20), our bootstrapping pr ...

SPRINGER INTERNATIONAL PUBLISHING AG2021

Improving First-Order Threshold Implementations of SKINNY

Subhadeep Banik, Andrea Felice Caforio, Ognjen Glamocanin, Daniel Patrick Collins

Threshold Implementations have become a popular generic technique to construct circuits resilient against power analysis attacks.In this paper, we look to devise efficient threshold circuits for the lightweight block cipher family SKINNY. The only threshol ...

Springer2021

Swap and Rotate: Lightweight Linear Layers for SPN-based Blockciphers

Serge Vaudenay, Francesco Regazzoni, Subhadeep Banik, Muhammed Fatih Balli

In CHES 2017, Jean et al. presented a paper on "Bit-Sliding" in which the authors proposed lightweight constructions for SPN based block ciphers like AES, PRESENT and SKINNY. The main idea behind these constructions was to reduce the length of the datapath ...

2020

A Study of Persistent Fault Analysis

Subhadeep Banik, Andrea Felice Caforio

Persistent faults mark a new class of injections that perturb lookup tables within block ciphers with the overall goal of recovering the encryption key. Unlike earlier fault types persistent faults remain intact over many encryptions until the affected dev ...

Springer2019

Generic Round-Function-Recovery Attacks for Feistel Networks over Small Domains

Serge Vaudenay, Fatma Betül Durak

Feistel Networks (FN) are now being used massively to encrypt credit card numbers through format-preserving encryption. In our work, we focus on FN with two branches, entirely unknown round functions, modular additions (or other group operations), and when ...

2018

Generic Round-Function-Recovery Attacks for Feistel Networks over Small Domains

Serge Vaudenay, Fatma Betül Durak

Feistel Networks (FN) are now being used massively to encrypt credit card numbers through format-preserving encryption. In our work, we focus on FN with two branches, entirely unknown round functions, modular additions (or other group operations), and when ...

ePrint2018

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

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

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

Multipurpose Cryptographic Primitive ARMADILLO3

Serge Vaudenay, Petr Susil

This paper describes a new design of the multipurpose cryptographic primitive ARMADILLO3 and analyses its security. The ARMADILLO3 family is oriented on small hardware such as smart cards and RFID chips. The original design ARMADILLO and its variants were ...

Springer2012

Dial C for Cipher

Thomas Baignères

We introduce C, a practical provably secure block cipher with a slow key schedule. C is based on the same structure as AES but uses independent random substitution boxes instead of a fixed one. Its key schedule is based on the Blum-Blum-Shub pseudo-random ...

Springer2007

Proving the Security of AES Substitution-Permutation Network

Serge Vaudenay, Thomas Baignères

In this paper we study the substitution-permutation network (SPN) on which Rijndael is based. We introduce Rijndael*, a SPN identical to Rijndael except that fixed S-boxes are replaced by random and independent permutations. We prove that this construction ...

2005