A secure and adaptive block-based image encryption: a novel high-speed approach

In the era of digital communication, ensuring the security of transmitted images is paramount, particularly for online and real-time applications where data privacy and integrity are essential. This paper introduces a novel image encryption algorithm designed to address the rigorous demands of such contexts, prioritizing both security and speed. Employing SHA-512 as the secret key and leveraging block-based encryption techniques, the proposed algorithm offers security and adaptability to various image sizes and aspect ratios, catering to the diverse needs of modern applications. The algorithm enhances security by incorporating chaotic systems for key generation and permutation while maintaining high-speed encryption and decryption processes. Performance evaluation demonstrates the algorithm’s resilience against common cryptographic attacks, underscoring its effectiveness in safeguarding sensitive image data in dynamic online and real-time contexts. Notably, the algorithm achieves encryption speeds of up to 438.49 Mbps for images sized 1080 × 1920, with an encryption time of just 0.108 s as well as 0.26 s for an image sized 2611 × 1800. For a Lena color image sized 512 × 512, the proposed algorithm results in an entropy of 7.999252, an NPCR value of 99.6365, a UACI value of 33.4542 and encryption time of 0.0254 s. With adaptability to diverse image characteristics and a robust defense against potential threats, the proposed algorithm emerges as a promising contender for ensuring the integrity and confidentiality of digital images in today’s interconnected world.