The Enigma machine was a device used by the Nazis to send encrypted messages to German attack submarines, which were inflicting heavy losses on Allied shipping during World War II. Now, 60 years after the end of the War, the last unsolved secret messages are being decrypted in a combined effort involving 1000’s of personal computers connected via the internet, running open source software available from the web.

Made famous in the Hollywood movie with Dougray Scott and Kate Winslett, the Enigma was an electro-mechanical device that converted keyboard presses into an electrical signal that was scrambled, and converted into a new letter. The resulting output appears as a sequence of random letters, such as this actual example below:

HCEY ZTCS OPUP PZDI UQRD
LWXX FACT TJMB HDVC JJMM
ZRPY IKHZ AWGL YXWT MJPQ
UEFS ZBCT VRLA LZXW VXTS
LFFF AUDQ FBWR RYAP SBOW
JMKL DUYU PFUQ DOWV HAHC
DWAU ARSW TXCF VOYF PUFH
VZFD GGPO OVGR MBPX XZCA
NKMO NFHX PCKH JZBU MXJW
XKAU OD?Z UCVC XPFT

The output message would be relayed by radio to a submarine captain, who would use his own device to decipher the message.

Earlier versions of the code were famously cracked by the Allies, perhaps shortening the War in Europe by two years. However, the Enigma machine was upgraded towards the end of the War and the final messages were never deciphered – until now.

In a joint internet project, the last three secret messages are being analyzed using a so-called “brute force” effect, combining the efforts of 2500 home computers to try each one of the 160 trillion different combinations of characters, until a sensible message appears.

After 3 months, the first of the three remaining unknown messages (shown above) has been cracked, and looks like it was sent after an attack by an Allied ship:

“Forced to submerge during attack. Depth charges. Last enemy position 0830h AJ 9863, [course] 220 degrees, [speed] 8 knots. [I am] following [the enemy]. [barometer] falls 14 mb, [wind] nor-nor-east, [force] 4, visibility 10 [nautical miles].”

There are still two final secret messages produced by the Enigma machine yet to be deciphered. If you want to participate in the project, you can download the necessary software from the “Message Breaking Project” website.

The Enigma device code-breaking software runs under Linux and all versions of Microsoft Windows.