International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Thomas Peters

Affiliation: UCL, Belgium

Publications

Year
Venue
Title
2020
TOSC
Towards Low-Energy Leakage-Resistant Authenticated Encryption from the Duplex Sponge Construction
The ongoing NIST lightweight cryptography standardization process highlights the importance of resistance to side-channel attacks, which has renewed the interest for Authenticated Encryption schemes (AEs) with light(er)-weight sidechannel secure implementations. To address this challenge, our first contribution is to investigate the leakage-resistance of a generic duplex-based stream cipher. When the capacity of the duplex is of c bits, we prove the classical bound, i.e., ≈ 2c/2, under an assumption of non-invertible leakage. Based on this, we propose a new 1-pass AE mode TETSponge, which carefully combines a tweakable block cipher that must have strong protections against side-channel attacks and is scarcely used, and a duplex-style permutation that only needs weak side-channel protections and is used to frugally process the message and associated data. It offers: (i) provable integrity (resp. confidentiality) guarantees in the presence of leakage during both encryption and decryption (resp. encryption only), (ii) some level of nonce misuse robustness. We conclude that TETSponge is an appealing option for the implementation of low-energy AE in settings where side-channel attacks are a concern. We also provides the first rigorous methodology for the leakage-resistance of sponge/duplex-based AEs based on a minimal non-invertibility assumption on leakages, which leads to various insights on designs and implementations.
2019
TCHES
TEDT, a Leakage-Resist AEAD Mode for High Physical Security Applications
We propose TEDT, a new Authenticated Encryption with Associated Data (AEAD) mode leveraging Tweakable Block Ciphers (TBCs). TEDT provides the following features: (i) It offers full leakage-resistance, that is, it limits the exploitability of physical leakages via side-channel attacks, even if these leakages happen during every message encryption and decryption operation. Moreover, the leakage integrity bound is asymptotically optimal in the multi-user setting. (ii) It offers nonce misuse-resilience, that is, the repetition of nonces does not impact the security of ciphertexts produced with fresh nonces. (iii) It can be implemented with a remarkably low energy cost when strong resistance to side-channel attacks is needed, supports online encryption and handles static and incremental associated data efficiently. Concretely, TEDT encourages so-called leveled implementations, in which two TBCs are implemented: the first one needs strong and energy demanding protections against side-channel attacks but is used in a limited way, while the other only requires weak and energy-efficient protections and performs the bulk of the computation. As a result, TEDT leads to more energy-efficient implementations compared to traditional AEAD schemes, whose side-channel security requires to uniformly protect every (T)BC execution.
2017
EUROCRYPT
2017
PKC
2017
TOSC
On Leakage-Resilient Authenticated Encryption with Decryption Leakages
At CCS 2015, Pereira et al. introduced a pragmatic model enabling the study of leakage-resilient symmetric cryptographic primitives based on the minimal use of a leak-free component. This model was recently used to prove the good integrity and confidentiality properties of an authenticated encryption scheme called DTE when the adversary is only given encryption leakages. In this paper, we extend this work by analyzing the case where decryption leakages are also available. We first exhibit attacks exploiting such leakages against the integrity of DTE (and variants) and show how to mitigate them. We then consider message confidentiality in a context where an adversary can observe decryption leakages but not the corresponding messages. The latter is motivated by applications such as secure bootloading and bitstream decryption. We finally formalize the confidentiality requirements that can be achieved in this case and propose a new construction satisfying them, while providing integrity properties with leakage that are as good as those of DTE.
2016
CRYPTO
2015
EPRINT
2015
EPRINT
2015
EPRINT
2015
PKC
2015
CRYPTO
2015
ASIACRYPT
2014
EUROCRYPT
2014
PKC
2014
ASIACRYPT
2013
PKC
2013
CRYPTO
2012
EUROCRYPT
2012
CRYPTO
2012
ASIACRYPT

Program Committees

PKC 2019
Asiacrypt 2019
Eurocrypt 2017