The Special Fish Report
Albert W. Small (December 1944)
Page 93
Tony Sale's
Codes and Ciphers
|
previous page
|
next page
|
index page
|
CX/MSS
TOP SECRET Special Fish Report Page 93
Other aids to key solution exist. The placing of rectangles
end-to-end as follow.:
..................................
| 1-5 | 2-5 | 3-5 | 4-5 |
to use data from wheels 1, 2, 3, and 4 simultaneously in getting out
the pattern for 5, has been found an aid. Results can be flagged in a 23x23
flag if desired, or the long rectangle can be converged by itself.
A "15O-square," which contains every possible delta Key i+j rectangle:
...............................
| 1-5 | 2-5 | 3-5 | 4-5 |.....|
| 1-4 | 2-4 | 3-4 |.....| 5-4 |
| 1-3 | 2-3 |.....| 4-3 | 5-3 |
| 1-2 |.....| 3-2 | 4-2 | 5-2 |
|.....| 2-1 | 3-1 | 4-1 | 5-1 |
is an even more powerful aid, but very seldom used. It is at least 3 feet
wide and takes a prodigious amount of time to construct and converge. A signifi-
cance test proposed when converging it is the famous "Significance Test IV:"
One half of X is used instead of X since the square counts everything twice.
Such a square when used gives a good start in Turingery, which Turingery usually
itself
needs; but Turingery/makes use of all the data appearing in the l50 square and
in addition uses motor dot information, so Turingery is actually more powerful
although slower to start.
|
previous page
|
next page
|
index page
|