Cipher

About: Cipher is a research topic. Over the lifetime, 9409 publications have been published within this topic receiving 110309 citations. The topic is also known as: cypher & cryptographic algorithm.

SNOW - A new stream cipher

Abstract: In this paper a new word-oriented stream cipher, called SNOW, is proposed. The design of the cipher is quite simple, consisting of a linear feedback shift register, feeding a nite state machine. The design goals of producing a stream cipher signi cantly faster than AES, with signi cantly lower implementation costs in hardware, and a security level similar to AES is currently met. Our fastest C implementation requires under 1 clock cycle per running key bit. The best attacks are generic attacks like an exhaustive key search attack.

A novel image encryption algorithm based on genetic recombination and hyper-chaotic systems

Abstract: In this paper, a novel image encryption algorithm based on genetic recombination and hyper-chaotic system is proposed. The basic rules of genetic recombination are employed to scramble images because of its effectiveness. Specifically, the plain image is expanded into two compound images composed of selected four bit-planes and diffuse them at bit-plane level, the compound bit-planes and key streams are reconstructed based on the principles of genetic recombination, then perform traditional diffusion and obtain cipher images. The hyper-chaotic Lorenz system in this algorithm generates pseudorandom sequences in each phase. The experiment results and analysis have proved that the novel image encryption algorithm is effective for image encryption.

A novel technique for the construction of strong S-boxes based on chaotic Lorenz systems

Abstract: In cryptographic systems, the encryption process relies on the nonlinear mapping of original data or plaintext to the secure data. The mapping of data is facilitated by the application of the substitution process embedded in the cipher. It is desirable to have resistance against differential cryptanalysis, which assists in providing clues about the composition of keys, and linear secret system, where a simple approximation is created to emulate the original cipher characteristics. In this work, we propose the use of nonlinear functional chaos-based substitution process which employs a continuous time Lorenz system. The proposed substitution system eliminates the need of independent round keys in a substitution-permutation network. The performance of the new substitution box is evaluated by nonlinearity analysis, strict avalanche criterion, bit independence criterion, linear approximation probability, and differential approximation probability.

Architectural support for fast symmetric-key cryptography

Abstract: The emergence of the Internet as a trusted medium for commerce and communication has made cryptography an essential component of modern information systems. Cryptography provides the mechanisms necessary to implement accountability, accuracy, and confidentiality in communication. As demands for secure communication bandwidth grow, efficient cryptographic processing will become increasingly vital to good system performance.In this paper, we explore techniques to improve the performance of symmetric key cipher algorithms. Eight popular strong encryption algorithms are examined in detail. Analysis reveals the algorithms are computationally complex and contain little parallelism. Overall throughput on a high-end microprocessor is quite poor, a 600 Mhz processor is incapable of saturating a T3 communication line with 3DES (triple DES) encrypted data.We introduce new instructions that improve the efficiency of the analyzed algorithms. Our approach adds instruction set support for fast substitutions, general permutations, rotates, and modular arithmetic. Performance analysis of the optimized ciphers shows an overall speedup of 59% over a baseline machine with rotate instructions and 74% speedup over a baseline without rotates. Even higher speedups are demonstrated with optimized substitutions (SBOXes) and additional functional unit resources. Our analyses of the original and optimized algorithms suggest future directions for the design of high-performance programmable cryptographic processors.

EME*: extending EME to handle arbitrary-length messages with associated data

Abstract: This work describes a mode of operation, EME*, that turns a regular block cipher into a length-preserving enciphering scheme for messages of (almost) arbitrary length. Specifically, the resulting scheme can handle any bit-length, not shorter than the block size of the underlying cipher, and it also handles associated data of arbitrary bit-length. Such a scheme can either be used directly in applications that need encryption but cannot afford length expansion, or serve as a convenient building block for higher-level modes. The mode EME* is a refinement of the EME mode of Halevi and Rogaway, and it inherits the efficiency and parallelism from the original EME.