A brute-force attack is available for encryption with the Twofish encryption algorithm.
The key space to be searched through is entered in the brute-force dialog. After the document has been decrypted with all the possible keys, the plaintext version of the document is assumed to be that which has the smallest entropy in the first thousand characters.
In the examples chapter there is an example of an attack on the triple-DES encryption algorithm in CBC mode. This example can be worked through for each of the symmetric encryption algorithms; however, the encrypted documents are always different.
Conditions which the document must satisfy for a successful attack: see brute-force attack.