JoWUA

Abstract

Unauthorized data access is rising due to the enhanced expansion of electronic data transfer. Information security is heavily relied on to protect data in storage and during transfer. However, protecting image data from similar means is paramount, mainly because images have become standard information actively used in a virtually endless list of applications and fields. This work proposes an image encryption technique that uses a Harris Hawks Optimization keys generator with a modified serpent algorithm by decreased round numbers and uses a sponge function to create dynamic eight unique substitution boxes (8-S-boxes). The empirical results confirmed that the modified encryption algorithm presents comparable security and superior performance to the classical Serpent. To evaluate the fitness of keys generated by a Harris Hawks Optimization, five standard tests of the National Institute of Standards and Technology successfully surpassed the fitness of the proposed keys generator. Several analytical tests were used to evaluate the encryption methods. These tests included histogram test, correlation test, entropy test, mean squared error, peak signal-to-noise ratio, unified average changing intensity, normalized pixel difference rate, and structural similarity index. The experiments showed that the suggested encryption method significantly improved all these tests. The computed information entropy value of 7.998 is quite near the ideal value of 8, indicating a high level of randomness. Further evidence of solid encryption was provided by a UACI value of 33.979 and an NPCR greater than 99.60%. The effectiveness of the decryption method was also verified.