U-534 Enigma M4 Messages Cracked

Enigma M4

I just received sensational news from Michael Hoerenberg. He succeeded in breaking 12 authentic Kriegsmarine messages, recovered from the German WW2 U-boat U-534, which were encrypted with the notorious four-rotor Enigma M4 cipher machine.

U-534 is one of the very few U-boats that were either salvaged or survived the war. U-534 was sunk in May 1945 by a British bomber. When she sank, she took with her the secret documents and equipment that were used to encrypt their communications. During the salvage of the U-boat, some of the original message sheets were recovered and preserved.

At this moment, Michael already managed to recover the key settings to 12 of the 59 available messages with his M4 WinEnigma (Turingbombe) and TBreaker software (and 112 CPU cores). Images of the original recovered message sheets and their plaintext version are published on his website.

The  breaking of these messages is fantastic news for the crypto community and Michael's achievement cannot be underestimated! Original messages, enciphered with the Kriegsmarine Enigma M4 (a much complexer encryption than the three-rotor machines of the Wehrmacht) are extremely rare and deciphered M4 messages are truly unique.

We are looking forward to the coming results of the codebreaking project. Please visit Michael's website Breaking German Navy Ciphers for more information about the codebreaking, the software and the recovered messages.

U-534 in Birkenhead, England, 2007

U-534 is currently displayed in the U-boat Story museum in Birkenhead, England. Pictures and video footage of the salvage is found on the Diveship TERNEN website. More about U-534 at U-boat Net.

For more information about the Kriegsmarine Enigma cipher machine, please visit the Enigma page on my website, where you can also download the popular freeware Enigma simulator (which can be used to decipher the original U-534 messages with the dicovered key setting).

Update 1: Michael also made available Kapitänleutnant Hartwig Looks' war diary of  U-264, containing the 25 November 1942 message that was solved in the M4 Message Breaking Project (see also M4 Project on my website).

Update 2: More sensational news from Michael. He managed to decipher the famous message, sent to all U-boats, that announced Great Admiral Dönitz as successor of Hitler (after his suicide) as new Fuhrer of the Reich. The original message form, ciphertext and decrypts are found at this page, and more info at the page Degarbling the Dönitz Message.

The Story of U-534's sinking and its salvaging

U-boat U534 story at Woodside in Birkenhead

Below a video of a part of the exhibition of U-534 in Birkenhead, UK, which also shows one partially and one completely recovered Enigma machine. Notice how well preserved all artifacts are.

U-534, a German World War Two U-Boat