7. By TITOGI.
T S S N I H A Y S T I N T P I S E R O O I A A S N.
Also this: S H C V I E O L E A E W E R M.
8. By G. A. SLIGHT. (Something found in every school-book - IF found!)
T G H M R R I A Y E X N U E E S D E X S H M T I D E Q U O A Y R O A U
N P U E T G T I T E S Y S N O A Q N X A T U A D S I S H X.
9. By PICCOLA.
W I N T A H D A E S W H L E T Y L W A I L H O Q L A S S S A S Q.
10. By NEMO. (Magic Square).
L E A S U L T S G M S L O E I E O I M E A R N S A S R C D E K I U S U
H E M A Q L Y S P R M E O A.
11. By THE ADMIRAL.
B S P N T E A E F T V V O A N E Y A P U Z S E T P T H M N A T A E E R
S D S S K P S J E S T Y S E A L R H I A S K S N T T E Y W O F T H M W
Y K E F E N N H C I E H H U M I H I T E O H G E S U C G D I O O W E A
S A S N E R H M A A S S L E R G S M N E D T H K E M L U A E T V M F O
R A I W P A Y A M A E Y A D.
12. By THE ADMIRAL.
A A F R S R T N E A R B N E E O H S R L T I A P D U E O S I I T T A T
G L F O T S O U S H H E P N Y.
13. By DAN SURR. (Received from General Headquarters following a skirmish).
F A A T R M N O A T I L V I S Y G U C F F I O O E P S N K L T O I N V
R T T O A H N D N E E R E N N B M P U N P O R R K A U O M E A N A I E
T S S B N R G T G S T T I E E I C T H R.
14. By PICCOLA. (This is serious advice!)
F F L T A A R N I E U O R N T O T D L A N R W S O I A T T E Y B A N T
M E H S K O G R Z E P S R E I O A O A M S S S M A L P I L Y S.
15. BY FRA-GRANT. (This might have been a little easier. Still - ?)
Q Y T E Y O F U B U Q E H I H T E C H T H S A U A O N S I T I T T T I
E T T E L L S E A P L T N T.
CHAPTER IV
Geometrical Types — The Nihilist Transposition
In the [preceding chapter], we glanced at the most elementary form of columnar transposition: a text is written into a block by rows and taken off by columns in such a way that even though all or part of the columns may be reversed in direction, these columns are always left standing one after another in regular order. Columnar transposition becomes less crude when the order for taking off the columns is an irregular one, governed by a changeable numerical key, the length of this key governing also the width of the rectangle. This process can be examined in Fig. 11. In this figure, the numerical key, 4 1 6 5 3 2 7, was first derived from a keyword, HALIFAX, according to the following very common plan: The two A’s, taken from left to right, receive the first two numbers; the third number, in the
| Figure 11 Usual Plan for Transposing Columns H A L I F A X 4 1 6 5 3 2 7 L E T U S H E A R F R O M Y O U A T O N C E C O N C E R N I N G J E W E L S X X X X Cryptogram: E R U C I L H M N E E X S O O C J X L A O E N E U, etc. |
absence of B, C, D, and E, is assigned to F; and so on, following the alphabetical rank of the letters present, and taking repeated letters from left to right. The presence of seven numbers implies seven columns, and it is said that the key-length is 7. When a text has been written into a block of that width, with a key-number standing above each column, these columns can be taken off in the order shown by the numbers, and not in regular sequence.
The key, used exactly as described, is a “taking off” key, and this is the common way of using one. It can, however, be used for “writing in” the successive units, placing the first letter of a given unit beneath number 1, the second letter beneath number 2, and so on until the seventh letter has been written below number 7, afterward beginning with the first letter of another unit below number 1 again. Under this plan the first unit of our figure, L E T U S H E, would have been written in in the order U L H S T E E. Since all units would follow exactly the same pattern, the resulting columns would be identical with those of the present block; the only essential difference would be that the new columns are already transposed, and can be taken off in straight order. The two resulting cryptograms, however, would not be the same. The unit which was written in in the order U L H S T E E, would have been in the order E H S L U T E had the method been that of taking out (or “off”).
The Nihilist transposition is ordinarily accomplished by “writing in,” and its numerical key is applied to both columns and rows. Thus its major unit is a square, and the seven-letter keyword HALIFAX, applied to both dimensions of a rectangle, demands a unit of 49 letters, while the shorter word SCOTIA, key-length 6, requires a unit of 36 letters.
Theoretically, this cipher is a double transposition, requiring two successive operations as shown in Fig. 12. But in practice, these two transpositions can take place simultaneously as pointed out in Fig. 13. The operator, having laid out his key-numbers at top and side of his square, begins his writing in the cell at which the column headed by number 1 crosses the row headed by number 1. He writes in his first unit, proceeds to the row numbered 2 for the writing in of his second unit, then to the row numbered 3, and so on, taking rows in the order shown by the numbers at the left, and placing the letters of his unit by following the numbers across the top. Thus, with only a little concentration, he has the entire major