by Chris Suslowicz
BATCO is short for BATtle COde not "British Army Tactical COde" as some references say.
1. BATCO is a paper numerical code. It has been specifically designed for ease of use, therefore the security protection it provides depends on strict adherence to the rules of use. Unauthorized adaptation of these rules weakens the code and is forbidden.
2. A BATCO sheet consists of 6 main parts which are:
a. Heading, The heading gives the edition, page and copy numbers
and space in which to record the period of use. An edition consists
of 36 pages.
b. Settings. On the left hand side are the cursor settings consisting
of 8 columns numbered 2 to 7, each comprising a scrambled alphabet. On
unit nets all six columns may be used, however the use of column 7 is
reserved and is only to be used on the authority of the unit commander.
On formation nets only 2 columns may be used for each net (see explanatory
notes at Appendix 1 (Page A1-2 of the manual)). A column number and letter, eg '2I' sets
the row of alphabet to be used (this is the same row set by '3D', '4F',
'5O', '6G' and '7O')
c. Cipher Alphabets. On the right hand side are the cipher alphabets,
comprising 26 horizontal lines of scrambled alphabet with the letters
printed in pairs. The plain text numbers 0 to 9 and two symbols are
printed at the top with 0 repeated. The cursor has the column numbers
and the plain text numerals and symbols engraved on it.
d. Spelling Box. The spelling box provides a method of spelling in BATCO.
e. Authentication Table. This table allows any station on the net to
challenge the authenticity of any other by requesting the details of a
2 figure number inside the box that corresponds to the intersection of
specific horizontal and vertical cursor. (See Appendix B)
f. Call sign and Starting Column Indicators. The starting position for
the encryption of text on nets is derived from the call sign indicator,
itself deduced from the list of letters in the bottom panel of the BATCO
sheet . All the letters of the alphabet are used, with the exception of Z which is reserved for use by
support helicopters as a fixed call sign indicator.
3. Vocabulary Cards.
a. Vocabulary cards are a method of representing plain text by substituting
and encoding numbers from 00 to 99. The inclusion of a word or phrase on
the vocabulary card does not mean it has to be encoded every time it
appears in the text of a message.
b. There is a series of different cards, an index is at Appendix 2, and
cards are reproduced at Appendix 3. Informal cards are not to be produced
by formations, units, or arms schools.
c. Cards 001-012 constitute the universal Unit Pack for use by all units.
They are supplemented as necessary by the special-to-arm and theatre cards
which make up the balance of the set. Examples of the use of the cards are
given at Appendix 4.
d. Card 012 is left blank and is intended to be used for encoding
supplementary information for a specific operation.
METHOD OF USE.
4. Rules for BATCO.
a. No unauthorized modifications.
b. Maximum of 22 encryptions per key setting. (Where combined length of a
question and its immediate answer is no longer than 22 digits, the same
row may be used.)
c. New key setting for each message. (But see b. above.)
d. Use key settings, as far as possible, in alphanumeric order.
e. Use key setting only once on each net.
f. Use PROWORDS that introduce encoded numerals:
- GRID (for grid references)
- NICK (for nicknumbers)
- DIRECTION (for target indication)
g. Obey the rules designed to maintain security of information. (See manual
Chapter 1 Paragraphs 115 to 117.)
Credits and References:
1) Chris Suslowicz <chris(at)suslowicz.org>