19.4 Interactive versus non-interactive attacks
In an interactive or online attack, Mallory must maintain a connection to and actively interact with her attack target Alice over the entire duration of the attack.
Figure 19.7 illustrates the working principle of an interactive attack. To carry out the attack, Mallory sends consecutive requests to Alice and processes Alice’s responses until the attack succeeds (or Mallory runs out of computational resources or time).
As an example, assume that Alice runs an SSH server configured to accept a username and a password at the login prompt. In that case, Mallory’s attempt to guess that username and password is an interactive attack. The only way Mallory can check whether her guess is correct is by actually entering the guess into Alice’s login prompt and, subsequently – maybe with the help of a script, checking whether the login attempt was successful or not. Hence, Mallory must actively interact with Alice for...