Design and analysis of Symmetric Cipher for Mobile Device Encryption Based on Extended Classical Techniques: VIgPLAY

Abstract

Nowadays, huge data concerning every human is travelling in all directions. So, data is crucial for everyone’s life. We need to secure this data. There are many scientists and researchers who have used various approaches for data security. We are well aware of the Cipher approach which converts message into an unreadable format (Cipher Text). In cryptography there are two types of Cipher’s: Substitution Cipher and Transposition Cipher. In this paper we have implemented a new symmetric cipher which has dual nature of Security along with this we have enhanced the structure of the matrix of Playfair Cipher (6*6) and Vigenère Cipher (36*36) which is supported for alphanumeric encryption in mobile app and LCG method for generate the random numbers. The VigPlay Cipher is built for speed and efficiency. In our results, it encrypted data in 1.63 ms and decrypted it in 0.98 ms, achieving a massive throughput of 200,231.48 KB/s on a lean 72.2 MB memory budget. Compared to heavyweights like AES, DES, and Blowfish, as well as classic ciphers like Playfair and Vigenère, VigPlay proves to be a faster, more lightweight alternative tailored perfectly for mobile app security. We combined Vigplay cipher with a dynamic substitution method (using an LCG) to create a much harder defense against common hacking methods, including brute-force attacks and frequency analysis. This hybrid approach makes the encrypted data far more random and highly sensitive to key changes, all while keeping things running fast. Our tests and charts prove that this model successfully delivers the best of both worlds: robust security that doesn't drag down execution speed or memory. This study provides a new dual-layer symmetric encryption technique that combines an enhanced 6x6 Playfair cipher and an enlarged 36x36 Vigenère cipher to permit alphanumeric input. Improved security against frequency analysis and brute-force attacks. The proposed method is suitable for mobile applications and resource-constrained environments and can be further extended using post-quantum cryptographic techniques and secure key distribution mechanisms for future secure communication systems.