Securing Text Messages using the Beaufort-Vigenere Hybrid Method

Abstract

Beaufort and Vigenere are fast and strong substitution encryption methods against brute force attacks if they have good key quality. But both of these methods by default can not produce a good avalanche effect. Avalanche effect is a measuring tool that can determine the strength of encryption from differential attacks. This research proposes hybrid techniques of Beaufort and Vigenere algorithms to optimize the security of text message encryption by modifying key generators. With this method, the encryption process can be done by input text messages and keys. The key is processed with a key generator to produce two new keys that are used for encryption using the Beaufort and Vigenere hybrid methods. Based on the test results, the Avalanche effect value rose significantly compared to the standard method, and the value of the avalanche effect was more stable and close to ideal compared to the previous method. The time required is also relatively very fast for the encryption or decryption process, experimental result shows it takes less than 0.1 seconds for more than 43 thousand of characters in the text message.