Lorenz SZ 40 style enciphering v5.0

Wheel start positions:                                

 

Cleartext:

 

Ciphertext:

Use

The most convenient way to use this cipher process is that of copy & paste. Virtually all Windows applications support copy & paste. Consequently any means of creating cleartext can be used e.g. Notepad, Word, Outlook, Excel. Alternatively, text displayed by Windows applications can be used e.g. MSIE, Adobe Acrobat Reader. 
The technique is to position the mouse cursor immediately to the left of the first character, click & hold the right mouse button and drag the mouse until the last character of the text is highlighted, then release the mouse button. Copy the highlighted text to the copy & paste buffer by holding down the control (Ctrl) key and pressing the C key, then release the control key. Click on the "Cleartext" area (above) and, with the text cursor flashing, paste the text into the area by holding down the control (Ctrl) key and pressing the V key, then release the control key. Once the ciphertext has been generated copy & paste can be used to insert it into the body of an email, for example. This way encrypted messages can be passed and only those who know the wheel settings for the message will be able to read it. Decryption of a message involves copying and pasting the ciphertext into the "Ciphertext" area, care is required to ensure that no spurious characters preceding the ciphertext are copied.
Used on-line there's a 1 in 372 chance of finding the chosen wheel setting; this is an extremely trivial number considering the potential chance of reading a message using this enciphering off-line, which is literally astronomical: it's the next best thing to unbreakable i.e. what Bletchley Park Cryptoanalysis Jack Good and Donald Michie referred to as the 'Motorless Tunny'.

To learn about the Lorenz SZ enciphering machine and Tunny, click on the following link:- http://en.wikipedia.org/wiki/Lorenz_cipher

INSTRUCTIONS

The wheels of the cipher machine must be set to a start position by entering a 12 character string (use letters and numbers only) in the box, and clicking on "Set wheels". It is important to remember your string otherwise encrypted messages can't be decrypted. This page loads with the string: AAAAAAAAAAAA preset, which can be used to see how it all works. 

Have you click "Set wheels"?

To Encrypt
Click inside the "Cleartext" area and the text cursor will flash in the top-left corner, then type the message you want encrypted. Click "Encrypt". The wheel positions will change during the encryption process, and when it is finished the encrypted version of your message will appear in the "Ciphertext" area. 

Example
Set the wheels using the preset string, or use couldbemagic

Type the following cleartext and click "Encrypt":-
This is a test message

its ciphertext is:-
RDPEBKJZQIZDQDD@YUILUHD using the preset string to set the wheels, or:-
RQHNGHTP|BHVIP@HEBYYOACW
using couldbemagic.

To Decrypt
Click inside the "Ciphertext" area and the text cursor will flash in the top left-hand corner (click "Clear all" to clear the area of any characters that may be displayed, beforehand). At this point ciphertext may be entered manually. However, it is far easier to use copy and paste for its entry - see "Use", opposite. As with encryption, the wheels must be set to their starting position before clicking "Decrypt" - see above for wheel setting.

Example
Set the wheels according to the same 12 character string used for the encryption. Either of the ciphertext given above can be pasted into the the "Ciphertext" area. On clicking "Decrypt" the cleartext will be displayed, only if you have used the same wheel settings!. Alternatively, set the wheels and click "Decrypt" to view the cleartext for the ciphertext currently displayed.