- 54 -
MEDIUM GRADE :
1. (of code or cipher systems). Designed to provide security, i.e.
resist breaking, for a comparatively short period, but for longer
than low-grade systems, and used especially in circumstances where
the apparatus and processes required by high-grade systems would
be unsuitable and long-term security is not essential.
2. (of Japanese cipher systems). Using unenciphered, i.e. plain,
indicators.
MENU :
(in Enigma). A series of more or less interconnected constatations
of which the relative positions are known, esp. such a series prepared
for key-breaking on the Bombe.
MESHING-POSITION :
Position where the two wheels of a Wheatstone cipher machine are in
mesh, i.e. where one plain language letter is exactly opposite a
cipher letter.
MESSAGE-TO-MESSAGE :
(of recurrences). Involving more than one message; external.
M.F., M/F :
Short for medium frequency.
MILK-RUN :
A series of two positional repeats of groups of reciphered code,
suggesting a possibility of depth.
MINOR DIFFERENCE :
The smaller of the two differences obtained when two code or cipher
groups are subtracted each from the other; it is not numerically
greater than a series of 5's.
MINOR GROUP :
That one of two code or cipher groups which, when subtracted from
the other group, produces the minor difference.
MINOR, v :
To express differences as minor differences only.
MINUEND :
A Beaufort Subtractor applied to code-groups by subtracting (non-
carrying) the code groups from it.
| previous page
| next page | index page |
