It has been established that quantum algorithms can solve several key cryptographic problems more efficiently than classical computers. As progress continues in the field of quantum computing it is important to understand the risks they pose to deployed cryptographic systems. Here we focus on one of these risks - quantum key-recovery attacks against ideal ciphers. Specifically, we seek to model the risk posed by an economically motivated quantum attacker who will choose to run a quantum key-recovery attack against an ideal cipher if the cost to recover the secret key is less than the value of the information at the time when the key-recovery attack is complete. In our analysis we introduce the concept of a quantum cipher circuit year to measure the cost of a quantum attack. This concept can be used to model the inherent tradeoff between the total time to run a quantum key recovery attack and the total work required to run said attack. Our model incorporates the time value of the encrypted information to predict whether any time/work tradeoff results in a key-recovery attack with positive utility for the attacker. We make these predictions under various projections of advances in quantum computing. We use these predictions to make recommendations for the future use and deployment of symmetric key ciphers to secure information against these quantum key-recovery attacks. We argue that, even with optimistic predictions for advances in quantum computing, 128 bit keys (as used in common cipher implementations like AES-128) provide adequate security against quantum attacks in almost all use cases.
MIBS is a light weight block cipher aimed at extremely constrained resources environments such as RFID tags and sensor networks. In this paper, we focus on improved key-recovery attacks on reduced-round MIBS with integral and zero-correlation linear cryptanalysis. By exploring the key-expanding properties and choosing suitable linear approximations with zero-correlation,13-round zero-correlation linear cryptanalysis were presented. Furthermore, we deduced some integral distinguishers from 8-round zero-correlation linear approximations using the relations between them, and as applications, we a…
BEAR, LION and LIONESS are block ciphers presented by Biham and Anderson (1996), inspired by the famous Luby-Rackoff constructions of block ciphers from other cryptographic primitives (1988). The ciphers proposed by Biham and Anderson are based on one stream cipher and one hash function. Good properties of the primitives ensure good properties of the block cipher. In particular, they are able to prove that their ciphers are immune to any efficient known-plaintext key-recovery attack that can use as input only one plaintext-ciphertext pair. Our contribution is showing that these ciphers are act…
Differential Fault Analysis of Lilliput under Random-Location Nibble Faults
School of Cyber Science and Technology, Hubei University（湖北大学网络空间安全学院）；Key Laboratory of Intelligent Sensing System and Security, Ministry of Education, Hubei University（湖北大学智能感知系统与信息安全教育部重点实验室）；Faculty of Mathematics and Statistics, Hubei Key Laboratory of Applied Mathematics, Hubei University（湖北大学数学与统计学院，湖北省应用数学重点实验室）
This paper presents a general strategy to recover a block cipher secret key in the cold boot attack setting. More precisely, we propose a key-recovery method that combines key enumeration algorithms and Grover's quantum algorithm to recover a block cipher secret key after an attacker has procured a noisy version of it via a cold boot attack. We also show how to implement the quantum component of our algorithm for several block ciphers such as AES, PRESENT and GIFT, and LowMC. Additionally, since evaluating the third-round post-quantum candidates of the National Institute of Standards and Techn…
In this paper, we report the first quantum key-recovery attack on a symmetric block cipher design, using classical queries only, with a more than quadratic time speedup compared to the best classical attack. We study the 2XOR-Cascade construction of Gaži and Tessaro (EUROCRYPT~2012). It is a key length extension technique which provides an n-bit block cipher with 5n/2 bits of security out of an n-bit block cipher with 2n bits of key, with a security proof in the ideal model. We show that the offline-Simon algorithm of Bonnetain et al. (ASIACRYPT~2019) can be extended to, in particular, attack …
In this paper, we propose a novel fault attack termed as Single Event Transient Fault Analysis (SETFA) attack, which is well suited for hardware implementations. The proposed approach pinpoints hotspots in the cypher's Sbox combinational logic circuit that significantly reduce the key entropy when subjected to faults. ELEPHANT is a parallel authenticated encryption and associated data (AEAD) scheme targeted to hardware implementations, a finalist in the Lightweight cryptography (LWC) competition launched by NIST. In this work, we investigate vulnerabilities of ELEPHANT against fault analysis. …
Xidian University（西安电子科技大学）；State Key Laboratory of Cryptology（密码学国家重点实验室）；National University of Defense Technology（国防科技大学）
In CRYPTO 2019, Gohr presented differential-neural cryptanalysis by building the differential distinguisher with a neural network, achieving practical 11-, and 12-round key recovery attack for Speck32/64. Inspired by this framework, we develop the Inception neural network that is compatible with the round function of Simeck to improve the accuracy of the neural distinguishers, thus improving the accuracy of (9-12)-round neural distinguishers for Simeck32/64. To provide solid baselines for neural distinguishers, we compute the full distribution of differences induced by one specific input diffe…
A Novel Semantic Manifold Alignment Attack against Embedding-to-Embedding Obfuscation in Privacy-Preserving LLMs
University of Houston（休斯顿大学）；The Chinese University of Hong Kong, Shenzhen（香港中文大学（深圳））；Waseda University（早稻田大学）；Stevens Institute of Technology（史蒂文斯理工学院）；National Taiwan University（国立台湾大学）
