Concept

Round (cryptography)

Publications associées (24)

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

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 Deeper Look at the Energy Consumption of Lightweight Block Ciphers

Francesco Regazzoni, Subhadeep Banik, Muhammed Fatih Balli, Andrea Felice Caforio

In the last few years, the field of lightweight cryptography has seen an influx in the number of block ciphers and hash functions being proposed. In the past there have been numerous papers that have looked at circuit level implementation of block ciphers ...

IEEE2021

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

Orthros: A Low-Latency PRF

Subhadeep Banik

We present Orthros, a 128-bit block pseudorandom function. It is designed with primary focus on latency of fully unrolled circuits. For this purpose, we adopt a parallel structure comprising two keyed permutations. The round function of each permutation is ...

2021

The Area-Latency Symbiosis: Towards Improved Serial Encryption Circuits

Subhadeep Banik, Muhammed Fatih Balli, Andrea Felice Caforio

The bit-sliding paper of Jean et al. (CHES 2017) showed that the smallest-size circuit for SPN based block ciphers such as AES, SKINNY and PRESENT can be achieved via bit-serial implementations. Their technique decreases the bit size of the datapath and na ...

2020

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

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

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

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

GIFT: A Small Present Towards Reaching the Limit of Lightweight Encryption

Subhadeep Banik

In this article, we revisit the design strategy of PRESENT, leveraging all the advances provided by the research community in construction and cryptanalysis since its publication, to push the design up to its limits. We obtain an improved version, named GI ...

2017

Some Cryptanalytic Results on Lizard

Subhadeep Banik

Lizard is a lightweight stream cipher proposed by Hamann, Krause and Meier in IACR ToSC 2017. It has a Grain-like structure with two state registers of size 90 and 31 bits. The cipher uses a 120 bit secret key and a 64 bit IV. The authors claim that Lizard ...

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

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

Improved Linear Cryptanalysis of Reduced-Round MIBS

Serge Vaudenay, Asli Bay, Jialin Huang

MIBS is a 32-round lightweight block cipher with 64-bit block size and two different key sizes, namely 64-bit and 80-bit keys. Bay et al. provided the first impossible differential, differential and linear cryptanalyses of MIBS. Their best attack was a lin ...

Springer2014

Low cost security for sensor networks

Christina Fragouli, Lorenzo Keller, Iris Safaka, Emre Atsan

We design and evaluate a lightweight encryption protocol suitable for sensor networks, that enables weak security in the presence of passive eavesdroppers. At every communication round, our protocol creates a key between each sensor node and the sink, by a ...

Institute of Electrical and Electronics Engineers Inc.2013

Statistical and Algebraic Cryptanalysis of Lightweight and Ultra-Lightweight Symmetric Primitives

Pouyan Sepehrdad

Symmetric cryptographic primitives such as block and stream ciphers are the building blocks in many cryptographic protocols. Having such blocks which provide provable security against various types of attacks is often hard. On the other hand, if possible, ...

EPFL2012

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 new class of diffusion layers constructed from several rounds of Feistel-like structures whose round functions a ...

Springer2012

Fault-Tolerant Facility Location: a randomized dependent LP-rounding algorithm

We give a new randomized LP-rounding 1.725-approximation algorithm for the metric Fault- Tolerant Uncapacitated Facility Location problem. This improves on the previously best known 2.076-approximation algorithm of Swamy & Shmoys. To the best of our knowle ...

Springer-Verlag2010

Linear (Hull) and Algebraic Cryptanalysis of the Block Cipher PRESENT

Pouyan Sepehrdad, Jorge Nakahara

The contributions of this paper include the first linear hull and a revisit of the algebraic cryptanalysis of reduced-round variants of the block cipher PRESENT, under known-plaintext and ciphertext- only settings. We introduce a pure algebraic cryptanalys ...

Springer Berlin / Heidelberg2009

Analysis of lightweight stream ciphers

Simon Fischer

Stream ciphers are fast cryptographic primitives to provide confidentiality of electronically transmitted data. They can be very suitable in environments with restricted resources, such as mobile devices or embedded systems. Practical examples are cell pho ...

EPFL2008