Wartime codes cracked
A German Enigma machine
Online amateurs crack Nazi codes
By Adam Blenford
Three German ciphers unsolved since World War II are finally being cracked, helped by thousands of home computers.
The codes resisted the best efforts of the celebrated Allied cryptographers based at Bletchley Park during the war.
Now one has been solved by running code-breaking software on a "grid" of internet-linked home computers.
The complex ciphers were encoded in 1942 by a new version of the German Enigma machine, and led to regular hits on Allied vessels by German U-boats.
Allied experts initially failed to deal with the German adoption in 1942 of a complex new cipher system, brought in at the same time as a newly upgraded Enigma machine.
The advancement in German encryption techniques led to significant Allied losses in the North Atlantic throughout 1942.
Forced to submerge during attack. Depth charges. I am following the enemy
Kapt Hartwig Looks
25 November 1942
The three unsolved Enigma intercepts were published in a cryptography journal in 1995 and have intrigued enthusiasts ever since.
Although assumed to have little historical significance, they are thought to be among just a handful of German naval ciphers in existence still to be decoded.
UNSOLVED CIPHER #1
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
He wrote a code-breaking program and publicised his project on internet newsgroups, attracting the interest of about 45 users, who all allowed their machines to be used for the project.
Mr Krah named the project M4, in honour of the M4 Enigma machine that originally encoded the ciphers.
There are now some 2,500 separate terminals contributing to the project, Mr Krah said.
"The most amazing thing about the project is the exponential growth of participants. All I did myself was to announce it in two news groups and on one mailing list."
Nevertheless, in little over a month an apparently random combination of letters had been decoded into a real wartime communication.
Ralph Erskine, who submitted the original intercepts to the journal Cryptologia in December 1995, told the BBC News website that cracking the German codes after more than 63 years would be an important milestone for amateur cryptologists.
"I think there is more satisfaction for people engaged in the project to know that they have been able to do something that Bletchley Park couldn't do," he said.
posted by Steve @ 11:44:00 AM