Dialog Hill Analysis (Known Plaintext)

You can reach this dialog vie the menu entry Analysis \ Symmetric Encryption(classic) \ Known Plaintext \ Hill.

The data required for the automatic analysis (Known Plaintext attack) for the Hill encryption algorithm must be entered in this dialog.

Accordingly, you should enter either the plaintext or the encrypted text, depending on the content of the active window prior to initiation of the automatic analysis for the Hill encryption algorithm.

If the active window contains the encrypted text, the plaintext must be entered into the dialog (in the Plain text or cipher text box) and the Plain text in input box option must be selected. This is done by clicking with the mouse button. If on the other hand the window that was active prior to invoking the automatic analysis contained the plaintext, then the encrypted text must be entered and the Cipher text in input box option must be selected.

The text can of course also be copied to this dialog from another window via the clipboard. This saves having to remember and type out longer texts. Further information on copying text into the clipboard will be found via the help facility offered on the CrypTool toolbar.

You have the option of limiting the dimension of the key to be searched for. If you know the length of the key, then you can instruct the program to confine the analysis to this key length. This can save a lot of time, especially if the document is large. However, you should note that, for example, that this will mean that a key of dimension 3 will not be found if you limit the dimension to 1 or 2.

To start the analysis, click on Continue; to terminate the analysis click on Cancel.

If CrypTool has been able to work out the key it will be displayed in the Key for Hill cipher ; otherwise a message stating that the key could not be found will appear.