The 1944 Bletchley Park Cryptographic Dictionary

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BANBURISMUS :

1. The use of Banburies to set messages (especially Enigma messages) in depth with each other. When two Banburies are superposed identical letters in the same position are readily seen by (the light which comes through) the coincident holes; the number of clicks for any relative position of the two messages can thus be readily counted, and when this shows a proportion to the length involved which corresponds to clear language frequency, the two messages are probably placed in depth.

2. Action or process of identifying right-hand and middle wheels of an Enigma machine by relating distances or intervals between message settings (as found by placing in depth, e.g. pairs of messages having the first letter of that setting, as enciphered on the Grundstellung, the same and one or both of the other two letters different) to the possible intervals between the enciphered settings, noting and scoring all possible partial alphabets so obtained, eliminating contradictions, and so fixing position of turn-overs (which serve to identify the wheels).

BANBURISMUS MENU :

A menu prepared from alphabets found by the above process and used to determine the thirdwheel and the stecker.

BANBURY :

1. A sheet or strip of paper having vertical alphabets printed across its width at equal intervals on which a cipher message can be reproduced by punching out the consecutive letters of the text in consecutive columns, designed to facilitate the placing of messages in depth; (see Banburismus 1).

2. (of results). Produced or obtained by the use of Banburies.

BANBURY, v :

To reproduce (a cipher text) by punching on a Banbury.

BASE :

1. True code-group or other substituted group or unit before recipherment, or after true key has been stripped.

2. Values arbitrarily assigned to code-groups when the true figures are not yet determined, such that the assigned value differs from the true by an amount which is constant for each group, and therefore the differences between groups is a true difference. (Usually distinguished from sense 1 by the words arbitrary, common, or provisional).

BASIC :

(of a code-group in process of identification). Established as being a particular part of speech (e.g. noun, verb, adjective) but not more precisely determined.

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