Which authentication method is effective in preventing authentication replay attacks?

The challenge/response mechanism is a robust authentication method that effectively prevents authentication replay attacks. This approach involves the server sending a unique challenge to the user (or client) during the authentication process. The user then combines this challenge with their secret (such as a password) to produce a response, which is sent back to the server for verification.

The reason this method is effective against replay attacks is that each challenge is unique and time-sensitive. Even if an attacker intercepts the response, they cannot replay it successfully, as they would not be able to generate an appropriate response to a new challenge that the server presents. This key feature—using different, ephemeral challenges—ensures that even if credentials are captured, they cannot be reused in a different session by an attacker.

In contrast, other methods like password hash implementation focus primarily on securing the password itself rather than addressing the dynamic aspects of the authentication process. While password hashes provide protection against certain attacks, they do not inherently prevent replay attacks unless combined with mechanisms like nonce or timestamp checks. Wired Equivalent Privacy (WEP) encryption primarily secures wireless communications but does not provide a direct method to prevent replay attacks during authentication. Similarly, basic authentication over HTTP involves simply re-sending credentials, making it vulnerable to