Open AccessTEDT, a Leakage-Resist AEAD Mode for High Physical Security Applications
Author(s) -
Francesco Berti,
Chun Guo,
Olivier Pereira,
Thomas Peters,
FrançoisXavier Standaert
Publication year - 2019
Publication title -
iacr transactions on cryptographic hardware and embedded systems
Language(s) - English
Resource type - Journals
ISSN - 2569-2925
DOI - 10.46586/tches.v2020.i1.256-320
Subject(s) - cryptographic nonce , side channel attack , computer science , authenticated encryption , encryption , block cipher , leakage (economics) , computer security , implementation , resilience (materials science) , block cipher mode of operation , cryptography , computer network , physics , economics , macroeconomics , programming language , thermodynamics
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.