A certain officer proposed to set up for this purpose a special military dictionary, similar to the marine signal-books existing in all countries. In this dictionary one could enter in alphabetical order all figures, letters, constantly occurring syllables, and complete military expressions. The officer in question was of the opinion that 3,000 ciphers would be quite enough to form a complete code. Thus all figures, letters, words, etc, would be numbered in the book in succession from beginning to end. In the preparation of reports one could then indicate by one cipher a figure, a letter, a syllable, and sometimes a whole word or even a whole phrase.
The disadvantage of such a system consists in that its foundation is always the same, and that the printed dictionary could easily be secretly obtained from all neighbouring States. In order to obviate this, a few alterations were subsequently proposed. One alteration was to the effect that one could take a given number to serve as a key; in preparing reports the key-number would always be added to the number under which is designated the required word in the dictionary. It may be assumed that the word “regiment” is required to be coded, and this word is number 500 in the dictionary; the key-number is 25; so in the report the word is indicated by 525. It is of course obvious that one could subtract, instead of adding, the key-number.
Another alternative consists in having two different key-numbers. In the report the words are indicated by figures always changing, first in the case of the one, and then of the other key-number. In this way one and the same word, indicated twice in the report, may each time be indicated differently. For instance, the word “division” is number 765 in the word-book; the key-numbers are 5,000 and 6,125. The first time the word “division” is indicated by the number 4,235 (that is, 5,000—765) and the second time by 5,360 (that is, 6,125—765).
The main disadvantage of all these various means of communication lies in that a book is essential, from which the deciphering will have to be done. The book in question is easily lost, or is not at hand at the required moment, and then the cipher is not only useless, but the work caused in obtaining the message is wasted.
An instance of this occurred in 1870, when one of the German generals received a message which he could not decipher at once, since the dictionary which the headquarter staff had arranged with him as a code-book was in a wagon which had been left behind. The same misfortune befell the commander of a French territorial division at Châlons-sur-Marne, who could not decipher a telegram, since by an oversight he had sent his cipher with the archives to Château Thierry.
For the ciphering of messages by spies the above systems are also disadvantageous because most spies can carry no books with them on their missions.
Thus writes Klembovski, who made a study of espionage on active service, but was unable to arrive at any method of transmitting messages which should be free of marked disadvantages. As to his contentions regarding the use of ciphers, it has been stated—though on what authority is hard to ascertain—that the German secret service will decipher any message in any language in a given space of time, no matter what code may be used. In one of Edgar Allan Poe’s stories there is a means shown of deciphering practically any code in which the characters are constant—that is, in which the same sign represents the same letter each time it is used—and it is quite probable that one used to the deciphering of code-messages could work out any code. For a code must be built up on some system, and therefore some reversal of the system must exist by means of which the message can be deciphered without the aid of a key.
Berlin recognises the uses of pseudo-clergy in time of war, for quite a number of German village clergy are impecunious and of a distinctly low class, and thus the army is not averse to their imposture. Men of this kind are selected for service in the field, where it is anticipated they can make themselves useful, under the pretext of ministering to the wounded, by extracting information about the movements of troops, etc. It is arranged that, in the event of a retreat, the clerical spy shall convey to the pursuing force detailed information regarding the losses in men and guns of those retreating, the numbers of men still unwounded, and the moral of the troops, by means of signals as detailed above—broken branches of trees, specially placed stones, and other things.
One favourite system of espionage on active service, from the German point of view, consists in the use of the Red Cross van. Under the rules governing international war, the Red Cross van may go anywhere, even into the enemy’s lines, to pick up wounded, and the German forces, “making war by all the violent means at their command,” have not scrupled to make use of Red Cross vans both for espionage work and as shelter for machine-guns—authentic cases are reported in which treacherous fire has been opened on the troops of the Allies in this way. Another method of obtaining information consists in sending two scouts out with a coil of wire, when in the presence of the enemy. The scouts, bearing one end of the wire, are instructed to approach the enemy’s lines, at night, and of course, when they have approached within sight, they are shot. The wire no longer “pays out” from the end kept in the lines, and the length unrolled, when hauled back and measured, gives the artillery-range almost to a nicety.
Communications in times of peace are never made direct to headquarters. The fixed spies, as already remarked, employ such agents as they may choose and their rate of pay allows. Their reports are collected by the travelling spies, who are under the control of agents of sections, stationed in Belgium and Switzerland (up to the outbreak of war) but not in Germany. From the agents of sections reports go to the Central Bureau of the secret service at Berlin, where sorting and classification of news supplied is pursued, and all that part of the world which could possibly be inimical to Germany is card-indexed. It is a sordid, sorry, mean business, utterly devoid of the romance and glamour with which the spy of fiction has invested it, and, whatever the fate of German armies in the field may be, the secret service of Germany has done more than anything else to pervert the moral sense of the nation.