Secure information transmission using the fractional coupled Schrödinger model: a dynamical perspective

In this work, the fractional coupled nonlinear Schrödinger model (FCNLSM) in optical fibre can exhibit chaotic dynamics with potential applications in cryptography and applied mathematics. This study investigates the dynamical properties of FCNLSM in optical fibre. The study depends on four steps. (1): The governing model is converted into an ordinary differential equation by employing a wave transformation. The soliton solutions not discussed in the literature are obtained by employing the new direct algebraic method. (2): The governing model is simplified into a dynamical system ( DS ). Through phase plane analysis, both perturbed and unperturbed behaviour of FCNLSM is observed. (3): The chaotic behaviour in the perturbed DS is characteristic and is harnessed for the design of an efficient encryption algorithm. The proposed encryption technique involves computing the hash digest of a plain image, which is then used to update the initial seed of the chaotic FCNLSM. The one-way function is employed to ensure the security of the encryption method. (4): The encryption and decryption coding is applied to confuse and diffuse the plain image, followed by decoding to generate the cypher image. The security performance of the proposed cryptosystem is evaluated using established metrics, demonstrating its resilience against various cryptanalysis techniques. Moreover, complexity analysis indicates the feasibility of practical implementation for the proposed algorithm.