Parallel Multi-core Implementation of the Optimized Speck Cipher

Abstract

Lightweight cryptographic algorithms like Speck, which are a family of block ciphers developed by the US National Security Agency (NSA), have become popular because of their efficient performance and small operational size. This paper introduces the execution on a parallel multi-core processor of the optimized version of the Speck cipher. However, this proposition fulfils the increased demand for developing quick and ultra-lightweight ciphers. In this work, this is addressed by optimizing the speck128/128 cipher by reducing its number of rounds to five. The optimization is accomplished by adding the dynamic substitution layer to increase the randomness of the cipher, which allows us to reduce the speck rounds. We conducted tests such as statistical, randomness, and cryptanalysis tests for linear and differential attacks on the optimized speck. The security results show that the optimized speck overcomes the original speck security level. The conducted experiments show that the new version of the speck runs faster than the original one in terms of execution time and throughput. The parallel execution over a multicore processor is applied, and its speedup ratio is equal to 2.64 when it's compared to the parallel execution of the original speck. Different message sizes and thread configurations are used in this work. The sequential execution of both speck ciphers is computed in terms of execution time and throughput, and the acceleration ratio of the optimized speck in this case is equal to 2.63.