Abstract:

The digital communication has expanded exponentially, thus increasing the level of protection of textual data required through some formidable encryption algorithm which can withstand advanced attacks. This paper introduces a new text encryption algorithm which is selected on the basis of twodimensional (2D) logistic map which utilizes chaotic dynamics to provide a high level of security properties. The 2D logistic map as adapted and implemented in our proposed framework is combined with coupling terms and perturbations in order to produce highly unpredictable chaotic sequences. The encryption algorithm is a two-stage algorithm: permutation of the positions of the characters based on a chaotic sequence and substitution based on dynamically generated key streams. The high sensitivity of key (diffusionrate > 99.5%), high randomness in the output of cipher texts ( entropy ≥ 7.98 ), and high resistance to frequency analysis attacks are shown by extensive security analysis. A comparative analysis with the classical ciphers such as Caesar, AES and stream ciphers indicates better performance in relation to security measures and computation speed. The algorithm has time complexity of O(n) and cryptographic strength that is appropriate to use in real-time applications. The algorithm proves its usefulness in the security of textual communications as experimented results confirm, with possible extrapolations of the algorithm to the IoT messaging systems and the hybrid multimedia encryption.