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AUTOCLAVE :
A cipher system in which successive groups of one or more letters
or figures are enciphered in a manner determined or partly determinod
by the key and/or plain language of the preceding group or a fixed
combination of preceding groups; a cipher having a self-generating
key.
AUXILIARY TABLE :
(in certain code-books which have two meanings assigned to one
group). That portion of the code which includes the second, or
subsidiary, meanings only; the employment of which is normally
indicated by a switch-group; cf. main table.
BABY :
BABY BRUTE FORCE :
Brute force methods applied to a selected portion of traffic,
especially to messages beginning on certain pages of a long
subtractor, when the indicator system is partly solved and the page
(but not the line and column) on which the messages begin is known.
BACKWARD CLICK :
(in Enigma). The occurrence of two different letters at the same
position in two messeges in depth with each other, associated with
the occurrence of the same two letters in the reverse order in the
two cribs.
BAG :
(in Met.).
1. (short for Bag of Stations). A set or group of meteorological
stations the observations from which are grouped together in a
collective broadcast.
2. Such a group of observations in a collective broadcast; (e.g.
the observations from stations in Holland form a "bag" in the
W. European collective from Berlin).
BAN :
Fundamental scoring unit for the odds on, or probability factor of,
one of a series of hypotheses which, in order that multiplication
may be replaced by addition, are expressed in logarithms. One ban
thus represents an odds of 10 to 1 in favour, and as this is too
large a unit for most practical purposes decibans
and centibans are
normally employed instead.
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