FINDING HIGHLY PROBABLE DIFFERENTIAL CHARACTERISTICS OF SUBSTITUTION-PERMUTATION NETWORKS USING GENETIC ALGORITHMS

Modeling Linear Characteristics of Substitution-Permutation Networks

In this paper we present a model for the bias values associated with linear characteristics of substitution-permutation networks (SPN's). The rst iteration of the model is based on our observation that for suuciently large s-boxes, the best linear characteristic usually involves one active s-box per round. We obtain a result which allows us to compute an upper bound on the probability that line...

Avalanche Characteristics of Substitution-Permutation Encryption Networks

Abstract — This paper develops analytical models for the avalanche characteristics of a class of block ciphers usually referred to as substitution-permutation encryption networks or SPNs. An SPN is considered to display good avalanche characteristics if a one bit change in the plaintext input is expected to result in close to half the ciphertext output bits changing. Good avalanche characterist...

Finding Most Probable Explanations Using a Self-Adaptive Hybridization of Genetic Algorithms and Simulated Annealing

Bayesian belief networks (BBN’s) are a popular graphical representation for reasoning under (probabilistic) uncertainty. An important, and NP-complete, problem on BBN’s is the maximum a posteriori (MAP) assignment problem, in which the goal is find the network assignment with highest conditional probability given a set of observances, or evidence. In this paper, we present an adaptive hybrid te...

Cryptanalysis of Substitution-Permutation Networks Using Key-Dependent Degeneracy

Data Hiding by LSB Substitution Using Genetic Optimal Key-Permutation

The least significant bit (LSB) embedding method is one of the most commonly used techniques; it targets the LSB's of the host image to hide the data. This paper deals with three main steganography challenges (i.e. capacity, imperceptibility, and security). This is achieved by hybrid data hiding scheme incorporates LSB technique with a key-permutation method. The paper also proposes an optimal ...

Provable Security of Substitution-Permutation Networks

Many modern block ciphers are constructed based on the paradigm of substitution-permutation networks (SPNs). But, somewhat surprisingly—especially in comparison with Feistel networks, which have been analyzed by dozens of papers going back to the seminal work of Luby and Rackoff—there are essentially no provable-security results about SPNs. In this work, we initiate a comprehensive study of the...