Security of Permutation-based Compression Function lp 231

In this paper, we study security of a certain class of permutation-based compression functions. Denoted lp 231 by Rogaway and Steinberger, they are 2n-to-n-bit compression functions using three calls to a single $n$-bit random permutation. We prove that lp 231 is asymptotically preimage resistant up to 2^{2n/3}/n query complexity and collision resistant up to 2^{n/2}/n^{1+e} query complexity for any e>0. Based on a single permutation, lp 231 provides both efficiency and almost optimal collision security

Combinatorics on words in information security: Unavoidable regularities in the construction of multicollision attacks on iterated hash functions

Classically in combinatorics on words one studies unavoidable regularities that appear in sufficiently long strings of symbols over a fixed size alphabet. In this paper we take another viewpoint and focus on combinatorial properties of long words in which the number of occurrences of any symbol is restritced by a fixed constant. We then demonstrate the connection of these properties to constructing multicollision attacks on so called generalized iterated hash functions.Comment: In Proceedings WORDS 2011, arXiv:1108.341

Efficient hardware implementations of high throughput SHA-3 candidates keccak, luffa and blue midnight wish for single- and multi-message hashing

In November 2007 NIST announced that it would organize the SHA-3 competition to select a new cryptographic hash function family by 2012. In the selection process, hardware performances of the candidates will play an important role. Our analysis of previously proposed hardware implementations shows that three SHA-3 candidate algorithms can provide superior performance in hardware: Keccak, Luffa and Blue Midnight Wish (BMW). In this paper, we provide efficient and fast hardware implementations of these three algorithms. Considering both single- and multi-message hashing applications with an emphasis on both speed and efficiency, our work presents more comprehensive analysis of their hardware performances by providing different performance figures for different target devices. To our best knowledge, this is the first work that provides a comparative analysis of SHA-3 candidates in multi-message applications. We discover that BMW algorithm can provide much higher throughput than previously reported if used in multi-message hashing. We also show that better utilization of resources can increase speed via different configurations. We implement our designs using Verilog HDL, and map to both ASIC and FPGA devices (Spartan3, Virtex2, and Virtex 4) to give a better comparison with those in the literature. We report total area, maximum frequency, maximum throughput and throughput/area of the designs for all target devices. Given that the selection process for SHA3 is still open; our results will be instrumental to evaluate the hardware performance of the candidates

JPEG steganography with particle swarm optimization accelerated by AVX

Digital steganography aims at hiding secret messages in digital data transmitted over insecure channels. The JPEG format is prevalent in digital communication, and images are often used as cover objects in digital steganography. Optimization methods can improve the properties of images with embedded secret but introduce additional computational complexity to their processing. AVX instructions available in modern CPUs are, in this work, used to accelerate data parallel operations that are part of image steganography with advanced optimizations.Web of Science328art. no. e544

A Novel Latin Square Image Cipher

In this paper, we introduce a symmetric-key Latin square image cipher (LSIC) for grayscale and color images. Our contributions to the image encryption community include 1) we develop new Latin square image encryption primitives including Latin Square Whitening, Latin Square S-box and Latin Square P-box ; 2) we provide a new way of integrating probabilistic encryption in image encryption by embedding random noise in the least significant image bit-plane; and 3) we construct LSIC with these Latin square image encryption primitives all on one keyed Latin square in a new loom-like substitution-permutation network. Consequently, the proposed LSIC achieve many desired properties of a secure cipher including a large key space, high key sensitivities, uniformly distributed ciphertext, excellent confusion and diffusion properties, semantically secure, and robustness against channel noise. Theoretical analysis show that the LSIC has good resistance to many attack models including brute-force attacks, ciphertext-only attacks, known-plaintext attacks and chosen-plaintext attacks. Experimental analysis under extensive simulation results using the complete USC-SIPI Miscellaneous image dataset demonstrate that LSIC outperforms or reach state of the art suggested by many peer algorithms. All these analysis and results demonstrate that the LSIC is very suitable for digital image encryption. Finally, we open source the LSIC MATLAB code under webpage https://sites.google.com/site/tuftsyuewu/source-code.Comment: 26 pages, 17 figures, and 7 table