Enhanced 3D Playfair Cipher Using Bcrypt and Goldbach Code Algorithms

With the rise in sophisticated cyberattacks and dependence on digital data, ensuring data security has become a significant concern. Cryptography has emerged as an effective method for protecting data, notably passwords, frequently used to authenticate and access sensitive data. Therefore, there is a need for highly secure encryption techniques to protect passwords. The paper proposes enhancing the 3D Playfair Cipher algorithm to address this issue. The 3D Playfair Cipher is a symmetric encryption scheme that uses a substitution technique and overcomes the limitations of the classical 5x5 Playfair Cipher by utilizing a 4x4x4 matrix. The proposed enhancement further improves the encryption scheme by increasing the matrix size to 16x4x4, integrating Bcrypt hashing algorithm and Goldbach code algorithmr. The avalanche effect evaluation results show a massive improvement from the original 3D Playfair Cipher, increasing from 1.39% to 56.58%. Furthermore, since the proposed algorithm uses a 16x4x4 matrix, there are 256x64x4 = 65536 possible trigraphs, and it would take 3.73605E+94 centuries to break the ciphertext through a brute force attack. This result indicates that the proposed enhancement provides a highly secure password encryption scheme.