Frequency Tables

Colum 1 Column 2 Column 3 Column 4 Column 5
A 11 A 111111111 A 1 A 1 A 11
B B 111 B 111 B B 1111111
C 1111111 C 1 C 111 C 1111 C
D 11 D 11 D 1 D D 111
E 1111 E E 11 E 1111111 E
F 111 F F 111111111 F 111 F 11111
G 111111111 G G 111 G 11 G 11
H 111 H 11111 H 111 H 111 H 11
I 11 I 11 I 1111111 I 11111111111111111 I 11
J 11111 J 1 J 111111 J J 111111111
K 111111 K 11111 K K 1 K 1
L L 1111111111111111111 L 11 L 11111 L 1
M M M 1111111 M 1111 M 111
N 1111111 N 111 N 1111 N N 11111
O 11111 O O 111111111 O 1 O
P 1111111 P 1111111 P 11111111 P 1111 P
Q 11111 Q Q Q 11 Q 111111
R R 1 R 1 R 111111 R 1
S S 11111111 S 111111 S 111111111111 S 1111111
T 1111111 T 111 T 11111 T 1 T 11111111111111
U 1111111 U 111 U 111111 U U 1
V 11111 V V 11 V 11111 V
W 111 W 1111 W W 11111 W 1111111
X 11 X X 1111 X 11111111 X 111111
Y 1111 Y 11111 Y Y 111 Y 1111111
Z Z 11111 Z 111 Z Z 111

In the table for Column 1, the letter G occurs 9 times. Let us consider it tentatively as E. Then if the cipher alphabet runs regularly and in the direction of the regular alphabet, C (7 times) = A and the cipher alphabet bears a close resemblance to the regular frequency table. Note TUV (= RST) occurring respectively 7, 7, and 5 times and the non-occurrence of B, L, M, R, S, Z, (= Z, J, K, P, Q, and X respectively.)

In the next table, L occurs 19 times and taking it for E with the alphabet running in the same way, A=H. The first word of our message, CT, thus becomes AM when deciphered with these two alphabets and the first two letters of the key are C H.

Similarly in the third table we may take either F or O for E, but a casual examination shows that the former is correct and A=B (even if we were looking for a vowel for the next letter of the keyword).

In the fourth table, I is clearly E and A=E. The fifth table shows T=14 and J=9. If we take T=E we find that we would have many letters which should not occur. On the other hand, if we take J=E then T=O and in view of the many E’s already accounted for in the other columns, this may be all right. It checks as correct if we apply the last three alphabets to the second word of our message, OSB, which deciphers NOW. Using these alphabets to decipher the whole message, we find it to read:

“M. B. Am now safe on board a barge moored below Tower Bridge where no one will think of looking for me. Have good friends but little money owing to action of police. Trust, little girl, you still believe in my innocence although things seem against me. There are reasons why I should not be questioned. Shall try to embark before the mast in some outward bound vessel. Crews will not be scrutinized so sharply as passengers. There are those who will let you know my movements. Fear the police may tamper with your correspondence but later on when hue and cry have died down will let you know all.”

The key to this message is CHBEF which is not intelligible as a word but if put into figures indicating that the 2d, 7th, 1st, 4th, and 5th letter beyond the corresponding letter of the message has been used the key becomes 27145 and we may connect it with the “personal” which appeared in the same paper the day before reading:

“M. B. Will deposit £27 14s 5d tomorrow.”