With known wheel-order, Ringstellung, and Stecker, the set-
ting of a message can be determined as follows. If a short
crib is available by (1) hand rodding and catalog, (2) click
machine (Br.), (3) grenade (Br. "Eel"). If no crib is avail-
able, by (1) "Eins" catalog (Br.), (2) Hypo, (3) Bull-dozer,
(4) Dud-buster (Army). Bull-dozer could be used even without
known Stecker.
Should long cribs for Duenna become unavailable, a device for
breaking Dora on a medium length crib would be desirable.
30 letters or crib is strong enough cryptographically to de-
termine it. Should even medium cribs become unavailable, a
statistical Duenna would be desirable, perhaps able to make
use also of a short crib. How long a message would be nec-
essary to develop sufficient cryptographic strength has not
been computed.
A number of minor German systems have employed Enigma mach-
ines. The German Armistice Commission in unoccupied France
and in French North A£rica has a ll-l5-l7 machine. Another
machine using three single-notch wheels was used by the German
railway traffic organization in Northern France. There were
probably many other such usages, but they all seem to be only
minor variants of standard systems and no special discussion
will be given here. These problems have been British for the
most part, since they intercept the traffic.