BATCO
by Chris Suslowicz

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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.)
 

BATCO wallet. (Photo via E-bay)

 
 

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Credits and References:

1) Chris Suslowicz <chris(at)suslowicz.org>
 
 
 

Mar 26/14