The 1944 Bletchley Park Cryptographic Dictionary

- 28 -

DESTECKER, v :

(in Enigma). To replace (the letters of a text or of a crib, or of the constatations obtained from a text and its crib) with the letters to which they are steckered or assumed to be steckered.

DESTECKERED :

(of letters in Enigma). Replaced by the letters to which they are steckered or assumed to be steckered.

DETYPEX :

To restore typexed matter to its original form by deciphering on a Typex machine.

DEVELOPMENT :

1. The utilization of the results of Research (when successful) and the application of the methods it has evolved, to break further, especially current, keys and settings; or (in the case of reciphered codes) to find further strippable depths, recover the reciphering key and break or reconstruct the underlying code-book; (cf. exploitation).

2. The complete list of different cipher alphabets produced by a cipher machine.

DF:

Direction-finding; a bearing or location obtained by this means.

DIAGONAL :

(in Enigma). The order in which the letters of the alphabet appear on the diagonal of the rod-square, determined by the order in which the letters (i.e. the keys) of the key-board are wired to the consecutive entry-points on the right side of the machine.

DIE :

(of a code or cipher system or any part thereof). To cease to be used; to become obsolete.

DIFFERENCE, n :

1. The results obtained when two groups (usually of code, or reciphered code that are in depth) are subtracted, usually non-carrying, the one from the other; a minor difference is one which is numerically less than a group of 5's; a major difference one which is greater.

2. The result obtained when two lengths of letter-subtractor cipher that are in depth with each other are subtracted; as such sub- traction eliminates the key, this result is the difference between the two plain-language texts.

| previous page | next page | index page |