In the first part of this paper the decorrelation theory of Vaudenay is analysed. It is shown that the theory behind the proposed constructions does not guarantee security against state-of-the-art differential attacks. In the second part of this paper the proposed Decorrelated Fast Cipher (DFC), a candidate for the Advanced Encryption Standard, is analysed. It is argued that the cipher does not...

Since the proposal of differential cryptanalysis and linear cryptanalysis in 1991 and 1993, respectively, the resistance to these cryptanalysis has been studied. In FSE2, Knudsen proposed a method of attacking block ciphers that used the higher order differential, and in FSE4, Jakobsen and Knudsen applied it to a cipher proposed by Nyberg and Knudsen. Their approach, however, requires large com...

Midori128 is a lightweight block cipher proposed at ASIACRYPT 2015 to achieve low energy consumption per bit. Currently, the best published impossible differential attack on Midori128 covers 10 rounds without the pre-whitening key. By exploiting the special structure of the S-boxes and the binary linear transformation layer in Midori128, we present impossible differential distinguishers that co...

TSC-4 is a T-function based stream cipher with 80-bit key, and proposed as a candidate for ECRYPT eStream project. In this paper, we introduce a differential method to analyze TSC-4. Our attack is based on the vulnerable differential characteristics in the state initialization of TSC-4, and for the chosen IV pairs, the differential probability is up to 2−15.40 in the case of weak keys. We show ...

In recent years, three main types of attacks have been developed against Feistel-based ciphers, such as DES[1]; these attacks are linear cryptanalysis[2], differential cryptanalysis[3], and the Davies and Murphy attack[4]. Using the discrete Fourier transform, we present here a quantitative criterion of security against the Davies and Murphy attack. Similar work has been done on linear and diff...

Midori is a light weight block cipher recently presented by Banik et al in ASIACRYPT 2015. There are two versions of Midori with state sizes of 64-bit and 128-bit respectively. The round function is based on Substitution-Permutation Network(SPN). In this paper, we give impossible differential cryptanalysis of Midori64. We studied the non-linear layer of the cipher and give two useful properties...

Private regression has received attention from both database and security communities. Recent work by Fredrikson et al. (USENIX Security 2014) analyzed the functional mechanism (Zhang et al. VLDB 2012) for training linear regression models over medical data. Unfortunately, they found that model accuracy is already unacceptable with differential privacy when ε = 5. We address this issue, present...

Most of recent collision attacks on SHA-0 are based on the differential path given by Xiaoyun Wang et al. Their disturbance vector was thought to be the best one. We noticed that the way they calculate number of sufficient conditions is not accurate, and we also found some new properties of the third Boolean function MAJ (b ∧ c) ∨ (c ∧ d) ∨ (d ∧ b). In this paper we present a new disturbance ve...

s of invited lectures Extended differential properties of cryptographic functions ANNE CANTEAUT (INRIA-Rocquencournt, France) Differential cryptanalysis is one of the very first attack proposed against block ciphers. This attack exploits the fact that some derivatives of the cipher (or of a reduced version of the cipher) have a nonrandom output distribution. Since this distribution highly depen...

This paper will attempt to explain some of the side-channel attack techniques in a fashion that is easily comprehensible by the layman. What follows is a presentation of three different attacks (power, timing and fault attacks) that can be carried out on cryptographic devices such as smart-cards. For each of the three attacks covered, a puzzle and it‘s solution will be given, which will act as ...