Modified Key Generation in Blowfish Algorithm
Nazia Siddiqui, Richa Gupta · SSRN Electronic Journal · 2018
Blowfish is a symmetric block cipher [64 bit] encryption algorithm with variable-length key, from 32 bit to 448 bit. The process involves 4-S boxes and P array which contains 18-32 bit values. As it is a symmetric key algorithm it uses same key for encryption and decryption of text. It includes 16 rounds and each round consists of XOR operation with P array and a function Feistel Network. The algorithm consists of two parts, key generation and data encryption which are evaluated simultaneously. In a general Blowfish algorithm, a random key is generated to be used in the process which is known to the sender and receiver. This proposal, discusses and implements a different approach to access the key which will be used in the algorithm, so that the exact key used in the algorithm is not known to the sender or the receiver.