Performance and security analysis using B-128 modified blowfish algorithm

Information security is a domain having extensive applications in the twenty-first century and beyond. Encryption is a technique used to prevent data from being accessed without authorization. Symmetric key encryption algorithms are extremely fast compared to asymmetric key algorithms and hence, are used widely. Blowfish is a symmetric key encryption algorithm that is unpatented, free-to-use, fast, compact, and efficient. It is also a very secure algorithm. But, its 64-bit block size prevents it from being widespread. The paper aims to propose a modified version of the Blowfish algorithm that performs high-speed encryption with high throughput and supports 128-bit block size, enhancing its applicability in various areas. The algorithm can be an alternative to the AES algorithm with limited power consumption. The proposed algorithm is compared with the original Blowfish algorithm based on execution speed, throughput, and the avalanche effect. The algorithm's performance is also evaluated on images based on diffusion properties, image histogram, entropy, and correlation coefficient.