The message deciphers:
YOU WILL PROCEED TO THE AVIATION CENTER AT MEUX WHERE THE DIRECTOR HAS _EEN ORDERED TO FURNISH YOU WITH A HI_H POWER _LERIOT AEROPLANE. YOU WILL THEN IN COMPANY WITH TWO FRENCH AVIATORS ASSI_NED _Y THE DIRECTOR PROCEED TO METZ AND DESTROY THE THREE ZEPPELINS REPORTED PREPARIN_ THERE FOR A RAID ON PARIS.
The substitution of B for G, G for W and K for V completes the cipher. This cipher is difficult only because the cipher alphabet is made up, not haphazard, but scientifically with proper consideration for the natural frequency of occurrence of the letters. In cipher work it is dangerous to neglect proper analysis and jump at conclusions.
In the study of Mexican substitution ciphers, several alphabets have been found which are made up in a general way, like the one discussed in this case.
Case 6-c.—It is a convenience in dealing with ciphers made up of numbers or conventional signs to substitute arbitrary letters for the numbers and signs. Suppose we have the message:
| ”??2& | 45x15 | )“8&# | &&1x4 | %&4&% |
| 6x?&” | 8&*x4 | 6°*°& | %“4&” |
By arbitrary substitution of letters this is made
| ABBCD | EFGHF | IJKDL | DDHGE | MDEDM |
| NGBDA | KDOGE | NPOPD | MAEDA |
This message is now in convenient shape to handle as Case 6-a and on solution is found to read: