In the digital age, chaotic map-based image encryption techniques play a crucial role in safeguarding multimedia content during transmission. To address performance and security challenges, we propose a new discrete chaotic system called the two-dimensional exponential-Tangent-Cosine System (2D-ETCS). Comprehensive dynamic analysis reveals that the system exhibits hyperchaos within the parameter range \(\theta \in (0, 1)\) , enabling its trajectories to cover the entire phase plane, making it an excellent candidate for cryptographic applications. Building on the 2D-ETCS system, we present a novel color image encryption scheme using an innovation cross permutation method. The process begins with a plaintext-related method that maps the parameters and initial values of the 2D-ETCS system, effectively increasing the system’s sensitivity to the plaintext. We then propose a cross-permutation method, which extracts pixels from the three color components under the control of chaotic sequences and reshuffles them to disrupt the pixel arrangement. After six rounds of cross-permutation, rotation, and mask operations, the final ciphertext image is generated. Security analysis and comparison confirm that the proposed encryption scheme offers robust security, making it well-suited for protecting image data in open-network communication tasks.
