Bangla and English Text Cryptography Based on Modified Blowfish and Lempel-Ziv-Welch Algorithm to Minimize Execution Time

The goal of this research is to provide data security without sacrificing data transfer speed especially for Bangla language in digital platforms such as e-commerce portals, online marketing, electronic banking, social media networks, mobile telecommunication etc. Different cryptography algorithms have been reviewed, and Blowfish and Lempel-Ziv-Welch (LZW) have been found suitable owing to various advantages. Blowfish, a symmetric block cipher algorithm, uses a variable-length key from 32 bits to 448 bits. It is unpatented, requires less memory to execute, fast, and simple to operate. The LZW algorithm is also simple to implement and works by building a dictionary adaptively. It is effective particularly against data loss. The implemented modified Blowfish algorithm is observed to be faster than LZW algorithm in terms of total time to encrypt and decrypt Bangla and English text. It is observed that modified Blowfish algorithm is the fastest (0.16ms) to encrypt Bangla text while LZW algorithm is the fastest (0.07ms) to decrypt Bangla text. It is also observed from inputting text of different packet size that on average Bangla text decryption is considerably slower than Bangla text encryption by modified Blowfish algorithm.