Paper & Pencil II.

This is coolbert:

Paper & pencil German. 

Conclusion.

Doppelkastenschliissel & RS-44.

It should not be also thought that ONLY the Japanese military continued to use what are called "pencil and paper" cryptographics during WW2!

The German Doppelkastenschliissel and Rasterschlussel 44 also pencil and paper cryptographs of some rather surprisingly high level of security, and NOT a machine.

The Doppelkastenschliissel cryptograph the knowledge of which was obtained only by CAPTURE on the battlefield!

"During the North African campaign, the British overran a German signal center and discovered the nature of the system."

"A World War II German Army Field Cipher and How We Broke it"

"The system was used by all levels of the German army, from army groups on down, seemingly where the highest-level means (Enigma) were not necessary or available. The encryption method was a clever variation of the Playfair that rendered breaking very difficult . . . To the enemy it was Doppelkastenschliissel (Two-Box Cipher)."

And from the German BuHa security web site we have a description of the German WW2 era field cipher Rasterschlussel 44. Paper and pencil again and not a machine but very effective. Used by army units in the field to secure their communications and doing so famously.

"RASTERSCHLÜSSEL 44 - THE EPITOME OF HAND FIELD CIPHERS"

"rs44 also served as a replacement procedure provided for the enigma. No other hand methods of the second world war ultimately proved as safe as the rs44. Allied designated the proceed as unbreakable when it was used correctly. Only 29% percent of intercepted rs44 news could be decrypted with an unbearably long time warp of about two weeks. Contrast, a quota is 72% decrypted Enigma messages, which could be deciphered also almost in real time."

Finally, thanks to the Geoff Sullivan web site Hut Six we have a download available of the RS 44 for your use - - free! Secure your own comms and good luck.

Granted that all these secure cryptographic methods are NOT unconditionally safe. But provide for what was at the time an adequate degree of secrecy.

Paper and pencil? Bowed but not broken? You judge.

coolbert.