An Improved Image Encryption Scheme Based on a Non-Linear Chaotic Algorithm and Substitution Boxes

World has become a global village after introduction of social media and social networks. However, it extensively increased the demand for network resources, particularly multimedia traffic like images, videos and audio. The medium for this extensive traffic is always public networks such as internet or cellular networks. But the open nature of such network like internet always creates security threats for data during transmission. Due to many intrinsic features and higher correlation in multimedia traffic, existing encryption algorithms are not very convincing to perform well under critical scenarios. Therefore, many people in the research community are still working to propose new encryption schemes which can address these issues and handle multimedia traffic effectively on public networks. In this paper, we explore the weaknesses of existing encryption schemes, which compromise in many scenarios due to high correlation of multimedia traffic. To tackle this issue we proposed certain enhancements in an existing scheme. Our enhanced modification includes addition of bitwise XORed operation using non-linear chaotic algorithm. Performance of enhanced scheme is tested against state of the art security parameters. Efficiency of the proposed scheme is also validated via entropy, correlation, peak signal to noise ratio, unified average change intensity and number of pixels change rate tests.