The password recovery software supports both dictionary and brute force methods. The first relies on known words while the second method will test all possible character combinations. A dictionary attack can only be successful if the creator has chosen a dictionary word as the password. Using dictionaries as the recovery method can be much faster than the brute force approach.

The recovery software is easy to use. All that needs to be done is to load a password protected zip file into the program’s interface. A dictionary has to be loaded if the dictionary recovery method is selected. The brute force recovery method requires a few additional parameters. The range of characters has to be selected as well as the minimum and maximum length of the password.

The password recovery software did test 13503531 passwords in 137 seconds on a Windows XP Service Pack 3 system with 4 Gigabytes of computer memory and a Intel Core Duo processor with 3.0 GHz. It would still take hundreds of years to test all possible password combinations of a size between 3 and 12 characters (alphanumerical).

Brute forcing makes therefor only sense if the password length is not greater than 6 unknown chars. It should also be noted that the recovery time is the maximum time needed. If the password length is lower it will not take that long.

The developer’s website contains dictionaries that can be used in the password recovery software.