A daily cipher puzzle on the Lorenz SZ40/42 cipher machine that Bletchley Park called Tunny, a cipher attachment used with a teleprinter.
Look up today's QEP number in the book, set the twelve wheels, and run the intercepted tape. Get it right and the teleprinter prints the message. Get one wheel wrong and you get garbage.
Normal: the QEP number is given and the teleprinter prints the message.
Twelve wheels, 501 cams, a new intercept every day at 00:00 UTC.
I'm Arthur. I made Skywave, and this is its sister. Tunny traffic went out by radio, which is how I got hooked on it... The machine logic follows the wartime reports as closely as I could manage. If you know better, email me.
This is a game. The wheel patterns and messages are made up for it, and nothing here is a real intercept. Not affiliated with or endorsed by Bletchley Park, The National Museum of Computing or the Crypto Museum.
The operator sent this QEP number in clear before the message. Find it in the book below and set the wheels to match.
Machine SZ40
Today
The operator sent the QEP number in clear, not enciphered, before the message. Read it off the tape: impulse 1 is the top hole.
| QEP |
|---|
Type a message and run it through the machine with the wheel settings below and today's cam patterns. Paste the tape back in with the same settings and you get your message back, because adding the same key twice cancels out.
Letters, figures, spaces and . , ? / ( ) : = + % ' work. Anything else is left out.
Just the five chi wheels, with no psi or motor wheels, so the key is the chi on its own. This matches the printable model. Type a cam pattern for each wheel (1 or x for a raised cam, 0 or . for a lowered one), set the start positions, then run it. The Worked example button loads the key printed on the model.
Click the arrows, drag a number up or down, or type it. Left to right as on the machine: psi, motors, chi.
Each row across the tape is one character: five holes, with the small sprocket hole between holes 2 and 3. The letter under each row is what the teleprinter printed.
Run the tape and the machine punches its output here.
No printer in hard mode. Read each row with the cheat sheet. Tap a row to mark it as read.
Punch the holes you see on the highlighted row of the tape. The matching line lights up on the cheat sheet. Pick the shift yourself, then type what you read in the box below.
Get the first 5 characters right and the rest fills in for you.
Now send a reply back. Leave the wheels on the settings you read the message with, type the reply, and the machine enciphers it and punches the tape.
Get the first 5 characters right and the rest fills in for you.