|Cipher disc for Werner Walti (real name Robert Petter), one of the|
spies who landed off the coast of Scotland in late September, 1940.
(After the Battle magazine).
Cipher discs were first described in a 1467 treatise by Leon Battista Alberti, an Italian Renaissance Man. Two discs, one larger than the other were pinned together and rotated around the pin. The message letters were commonly on the outside of the disc and the ciphered results were on the inside disc. Thus, using the disc at right, the word "cipher" would become "hwepgx". A variation of the Alberti cipher disc was also used during the American Civil War. The Germans took the standard cipher disc and added their own particular twist to it, adding numbers on both the inside and outside wheel. Handwritten on heavy card stock, the German cipher discs varied from agent to agent but were helpfully numbered sequentially by their spymasters.
|Outer circle of Josef Jakob's cipher disc.|
|Inner circle of Josef Jakob's cipher disc.|
|Josef Jakobs' cipher disc fragments held|
at the National Archives.
(photo copyright G.K. Jakobs)
As for Josef Jakobs, the fact that he had torn up his cipher disc did not bode well for him. MI5 interpreted Josef's act, committed during the pain-filled darkness of a frigid January night, as a hostile act. Had Josef really intended to help the English, they argued, he would have handed his intact cipher disc over to the English authorities when he was captured the following morning. Josef said that he had been overcome by pain and was afraid that peasant farmers would treat him harshly if they saw obvious spy equipment. The officers of MI5 and the members of Josef's court martial did not agree. Other German agents had also disposed of their cipher discs and/or codes prior to capture. Josef Waldberg and Karl Meier who landed along the coast of Kent in the darkness of an early morning in September 1940 had dumped their circular codes overboard after hearing a British patrol boat in the distance.
Perhaps Josef had lost his head because of the pain of his broken ankle, but his pleas were of no avail. In the end, those torn fragments of a cipher disc sealed Josef Jakobs' death sentence.
National Archives, Security Service files on Josef Jakobs - KV 2/24, 2/25, 2/26, 2/27.
German Spies in Britain, After the Battle Magazine, Volume 11, 1976.