Publications related to Cryptanalysis

Isogeny Problems with Level Structure

Given two elliptic curves and the degree of an isogeny between them, finding the isogeny is believed to be a difficult problem—upon which rests the security of nearly any isogeny-based scheme. If, however, to the data above we add information about the beh ...

2024

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

Temperature Impact on Remote Power Side-Channel Attacks on Shared FPGAs

Mathias Josef Payer, Mirjana Stojilovic, Ognjen Glamocanin, Hajira Shafqat Bazaz

To answer the growing demand for hardware acceleration, Amazon, Microsoft, and many other major cloud service providers have included field-programmable gate arrays (FPGAs) in their datacenters. However, researchers have shown that cloud FPGAs, when shared ...

IEEE2023

Bridging the gap between theoretical and practical privacy technologies for at-risk populations

Kasra Edalatnejadkhamene

With the pervasive digitalization of modern life, we benefit from efficient access to information and services. Yet, this digitalization poses severe privacy challenges, especially for special-needs individuals. Beyond being a fundamental human right, priv ...

EPFL2023

Attacks on some post-quantum cryptographic protocols: The case of the Legendre PRF and SIKE

Novak Kaluderovic

Post-quantum cryptography is a branch of cryptography which deals with cryptographic algorithms whose hardness assumptions are not based on problems known to be solvable by a quantum computer, such as the RSA problem, factoring or discrete logarithms. This ...

EPFL2022

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

Atom: A Stream Cipher with Double Key Filter

Subhadeep Banik, Willi Meier, Andrea Felice Caforio

It has been common knowledge that for a stream cipher to be secure against generic TMD tradeoff attacks, the size of its internal state in bits needs to be at least twice the size of the length of its secret key. In FSE 2015, Armknecht and Mikhalev however ...

2021

Towards Efficient LPN-Based Symmetric Encryption

Serge Vaudenay, Sonia Mihaela Bogos, Dario Korolija, Thomas Locher

Due to the rapidly growing number of devices that need to communicate securely, there is still significant interest in the development of efficient encryption schemes. It is important to maintain a portfolio of different constructions in order to enable a ...

Springer International Publishing AG2021

Complete Practical Side-Channel-Assisted Reverse Engineering of AES-Like Ciphers

Subhadeep Banik, Muhammed Fatih Balli, Andrea Felice Caforio

Public knowledge about the structure of a cryptographic system is a standard assumption in the literature and algorithms are expected to guarantee security in a setting where only the encryption key is kept secret. Nevertheless, undisclosed proprietary cry ...

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

Full key recovery side-channel attack against ephemeral SIKE on the Cortex-M4

Aymeric Genet, Natacha Yolande Emmanuel Marie Linard de Guertechin, Novak Kaluderovic

This paper describes the first practical single-trace side-channel power analysis of SIKE. While SIKE is a post-quantum key exchange, the scheme still relies on a secret elliptic curve scalar multiplication which involves a loop of a double-and-add procedu ...

2021

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

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

Classical Misuse Attacks on NIST Round 2 PQC: The Power of Rank-Based Schemes

Serge Vaudenay, Loïs Evan Huguenin-Dumittan

The US National Institute of Standards and Technology (NIST) recently announced the public-key cryptosystems (PKC) that have passed to the second round of the post-quantum standardization process. Most of these PKC come in two flavours: a weak IND-CPA vers ...

Springer, Cham2020

Analysis of the BIKE post-quantum cryptographic protocols and the Legendre pseudorandom function

Dusan Kostic

The field of post-quantum cryptography studies cryptographic systems that are secure against an adversary in possession of a quantum computer. In 2017, the National Institute of Standards and Technology (NIST) initiated a process to standardize quantum-res ...

EPFL2020

Misuse Attacks on Post-quantum Cryptosystems

Serge Vaudenay, Loïs Evan Huguenin-Dumittan, Abdullah Talayhan, Fatma Betül Durak, Ciprian Baetu

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

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

Practical Private Range Search in Depth

Odysseas Papapetrou, Ioannis Demertzis

We consider a data owner that outsources its dataset to an untrusted server. The owner wishes to enable the server to answer range queries on a single attribute, without compromising the privacy of the data and the queries. There are several schemes on “pr ...

2018

Performance characterization of Altera and Xilinx 28 nm FPGAs at cryogenic temperatures

Edoardo Charbon, Harald Arjan Robert Homulle

Quantum computers enable a massive speed-up in calculations, thanks to the nature of quantum operations. To unlock quantum computation, a classical system infrastructure is required for the control of qubits and processing of their data. While qubits are g ...

2018

On Secure Cloud Computing for Genomic Data: From Storage to Analysis

Zhicong Huang

Although privacy is generally considered to be the right of an individual or group to control information about themselves, such a right has become challenging to protect in the digital era, this is exemplified by the case of cloud-based genomic computing. ...

EPFL2018