DITA: A Dynamic Image-Based Authentication Protocol for Secure Network Communication Against Replay and Eavesdropping Attacks

Tokens are widely used to secure client–server communications in systems based on automatic authentication. These tokens can be vulnerable to hacking, as an attacker can impersonate a real user by eavesdropping on their communications. In this paper, we propose a new authentication mechanism that generates a random token for each authentication. The token consists of confidential data and is encrypted using random coordinates from a securely stored confidential image. The client uses a random session key to encrypt the confidential image, then encrypts the token using randomly selected coordinates by matching ASCII character values with pixel values. The results and analysis demonstrate improved resistance to credential theft, replay attacks, and passive eavesdropping under the stated security assumptions. Even if hackers crack the encrypted token, decryption is difficult because the encryption method relies on values unrelated to the original authentication data. Comparison results also demonstrate efficiency and reliability compared to existing systems, as well as their ability to withstand brute-force attacks, with the entropy of the probability distribution being the best.