Tag Archives: Enigma Event

Decode the Enigma: Crypto Transmission from KPH on Saturday, July 23, 2022

The Maritime Radio Historical Society is hosting a brilliant on-the-air event via KPH. I’ve pasted full details below, copies directly from the Maritime Radio Historical Society announcement:


Crypto Transmission from KPH!


The MHRS in cooperation with our good friends at the Cipher History Museum

will send a coded message in 5-letter groups via the facilities of coast stations KPH on Saturday July 23, 2022. The message will be encrypted using the famous Enigma code machine.

All KPH listeners are invited to try their hand at receiving and decrypting the message. Certificates will be awarded for proof of successful decode, first to decode and use of original hardware.

Mislaid your Enigma code machine? In the military you’d have some explaining to do, soldier. But for the KPH Crypto Event, no problem. See the ‘Enigma Simulator’ section below for a link to an easy-to-use Enigma simulator.


The Enigma was the Germans’ most sophisticated coding machine for securely transmitting command and control messages via radio communications in WWII. It was considered so secure that it was used to encipher the most top-secret of messages.

The arrangement of Enigma’s rotors and plugboard connections provided a unique series of letter substitutions which changed with each keystroke. The daily rotor order and the ring and plugboard settings to be used were specified in a codebook distributed monthly to all users of a network.

For additional information on the Enigma please see Ralph Simpsons’ Cipher Museum History site

Crypto broadcast date, time and formats.

The crypto broadcast will commence at 2000Z (1300 Pacific) on 23 July on all KPH CW frequencies. The broadcast will consist of a ‘callup’ (in plain text) announcing the broadcast, followed by the cipher message. The callup and cipher messages will be sent at 15 WPM. The cipher message will be sent in 5 letter groups and the message will be sent twice to ensure proper reception.

The usual KPH channel marker or ‘wheel’ running at 20 WPM will precede the announcement for the crypto broadcast to give listeners a chance to tune to the strongest signal in their area.

The KPH CW frequencies are (in kc):

    • 426 (after an announcement on 500)
    • 4247.0
    • 6477.5
    • 8642.0
    • 12808.5
    • 17016.8
    • 22477.5

Upon completion of the CW transmissions, the broadcast will be repeated on all KPH RTTY frequencies. The RTTY transmission will be 170cps shift Baudot, 45 baud.

The KPH RTTY frequencies are (in kc):

    • 6324.5
    • 8427.0
    • 12585.5

Code Machine Key Settings – IMPORTANT!

Decoding an Enigma message requires the use of two keys: a Daily Key (valid for particular day), and a Message Key (unique to each individual message sent that day).

The Daily Key

Prior to decoding a message, the daily key must be set into your Enigma code machine. The daily key settings were specified in codebooks and distributed monthly. Please consult the following codebook to obtain the daily key setting for the GMT date of the broadcast.

Click HERE for the Enigma codebook. Use the “Armee-Stabs-Maschinenschlussel No 28” (Army Staff Machine Key Number 28). Notice each daily setting is across one line, starting with the first day of the month on the bottom of the sheet.

The Message Key

Starting in 1940, for additional security, the machine operator would randomly choose two groups of three letters to encode each message (in addition to the daily key settings above). These were known as the ‘message key’. The first group of three letters is used to encode the second group of three. Then the first group (in plaintext) and the second group (now encoded) are sent in the message header, along with the date and letter count, as explained in the above link. The recipient then uses the message key to decode the message. For more information see the following video on Enigma decoding procedures.

Click HERE to watch a video on Enigma coding procedures.

Enigma Simulators

So you had to toss your Enigma machine overboard when your U-boat was captured? Again, no worries. MHRS has you covered! Software simulations exist for the Enigma code machine.

Click HERE for an Enigma simulator. It is web-based, no download necessary.


Upon proof of successful decode, the following certificates will be awarded:

– First to decode the Enigma message

– Successful decode using *original* hardware (i.e., an actual Enigma machine)

– All successful decodes of the message

To apply for a certificate, send the decoded message to info@radiomarine.org with the subject line ‘decoded Enigma message’. The First to Decode award will be based on the timestamp of the first email demonstrating a successful decode. For the Enigma Original Hardware certificate, send the decoded message *plus* a photo of your Enigma machine showing the daily key setting. Printed certificates will be mailed for ‘First-to-Decode and ‘Original Hardware’ awards. Certificates for ‘Successful Decode’ will be emailed in digital form suitable for printing at home.

More Information

For more information or questions about the KPH cipher broadcast send email to info@radiomarine.org with the subject line:

Crypto Broadcast

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Bletchley Park replica Turing Bombe decodes 40M Enigma message

Remember the weekend 40 meter Enigma message transmitted by DL0HNF? At least one recipient decoded this message:

(Source: Southgate ARC)

40m Enigma Message decrypted at Bletchley Park

On Friday, April 7 the amateur radio station DLØHNF transmitted an Enigma encrypted message on 7036 kHz to Bletchley Park

DLØHNF is the club station at the Heinz Nixdorf Museum in Paderborn, Germany. The encrypted telegraphy message they transmitted was received at the home of the World War Two UK Codebreakers in Bletchley Park. There the message was fed into a replica of the Turing Bombe which enabled the encryption to be cracked.

The message read:  “Paderborn greets the Codebreakers at Bletchley Park”

Read the report and pictures of the event down the page at

Bletchley Park

I would have loved to watch the Touring Bombe in action!

Out of curiosity, did anyone record the Enigma transmission?  I’ve had a number of readers inquire about this. Please comment!

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April 7: Decipher an Enigma encrypted message on 40 meters

(Source: Southgate ARC)

Enigma encrypted message to be sent in 40m

In cooperation with Bletchley Park, the Heinz Nixdorf Museum DLØHNF in Paderborn, Germany is hosting a cipher event on April 7

A Google translation of the DARC post reads:

As with the first event of this kind ten years ago, an encrypted message is sent over radio, to which radio amateurs are invited, to follow them and to play with them. This time, however, the message is not generated with a Lorenz machine, but with an enigma and then transmitted in encrypted telegraphy to 40 m from the club station of the Heinz Nixdorf Mueseum, DLØHNF.

DLØHNF will open radio stations with other stations, which also use historical technology and thus recreate a historical radio network, between the transmissions of various encrypted messages – which are specially approved for this event. DLØDM and DLØAFM are also involved. The activities in Bletchley Park go back to the mathematician Alan Turing, who during the Second World War succeeded in decoding the Enigma coded radio spoofs of the Germans with his Turing machine.

In the Heinz Nixdorf Museum you can watch the happenings from 9 o’clock on the spot. Visitors experience encryption with the Enigma, the Morse as well as a live transmission.

A precise frequency for the transmission of the CW transmission from 9:30 is not known. The museum information is at

Source https://www.darc.de/

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The Enigma Event: an on-air exchange of encrypted messages


(Source: Southgate ARC)

Members of the ARI Fidenza will be activating special callsigns IO4ENG and IQ4FE during the ‘Enigma Event’.

The Enigma Event consists of exchanging ham radio messages over the air encrypted with the Enigma code of WW II memory to commemorate its importance in the history of communications and encryption.

The Event Enigma is one of the “European Researchers’ Night” events on Sept 25th, when a number of initiatives will be organized by European research and cultural institutions.

An Amateur Radio Award (ENIGMA AWARD) is associated with this event. The ham activity of the ENIGMA AWARD will start on Sept. 12th.

All details and rules are available on the official Web site at: http://www.enigma-reloaded.it

This should be a fun event to hear on the air and one of the very few sponsored by ham radio operators who will intentionally transmit “encrypted” messages.  I will try to tune in.

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