Performance Evaluation and Design of B-128 Modified Blowfish Algorithm.

The field of information security has many uses in the modern day and beyond. Encryption is a method used to secure information from unauthorized access. Since symmetric key algorithms can decrypt data much more quickly than asymmetric key algorithms, the former are more popular. Blowfish is an unpatented, freely useable, compact, quick, and efficient symmetric key encryption technique. Additionally, this method has a high level of security. The size of its blocks (64 bits) is limiting its use, though. 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.