CIPHER WRITING, a method of sending important intelligence in a manner so effectually disguised that only those for whom the com munication is intended can understand the meaning of what is written. Till comparatively recent years diplomats, statesmen and military or naval commanders were the principal per sons compelled by circumstances to keep their affairs or their intended movements shrouded in secrecy. So long as there was not regular postal service important letters were sent by courier, and thus the weightiest secrets were often at the mercy of any one inclined to be dishonest. Before the spread of education, and at a time when few possessed a knowledge of any other language than their own, to indite a letter or dispatch in a foreign tongue was usually ample protection against a surreptitious prying into its contents. But this safeguard has broken down, and it became necessary for all who did not want their correspondence known to interested parties to contrive some means of communicating with the pen that would defy scrutiny.
Hence there came into extensive use the art of writing in cipher, called also cryptography, from the Greek words stpvirr6c, *secret," and room, *to write.* Under this term are in cluded all private alphabets or systems of characters for the safe transmission of A popular cipher for ordinary purposes is found by using the alphabet in an inverted order. taking Z for A, Y for B, X for C and so on. When it is only desired to write a cryptogram, and not print it, such other characters may be used as are mutually agreed upon by corre spondents, or the alphabet may be transposed in other ways. A figured cipher is one in which the letters of the alphabet are numbered and these numbers compose the cryptogram. To ensure secrecy it is, of course, necessary that the particular series of numbers chosen shall be known only to those who use the cipher. Another plan consists in choosing a certain book— a dictionary appears to have been the favorite—and by a simple citation of the num ber of the page, of the column and of the line, sentences were constr,peted, the key to which was extremely difficult of discovery by one not in the secret.
As the number of different dictionaries was necessarily limited, however, the mystery could usually be solved by any one willing to devote time and patience to hunting up the particular one adopted. Various other books have been similarly used, such as spelling books, and even the Bible; but these systems are cumbersome, and were all more or less open to detection. From a few rules, as for instance, that in Eng lish e is the letter which most frequently occurs, and the the most common word, the whole might generally be deduced. The task of de tecting cipher methods is rendered much more difficult when false characters, which are not to be counted, have been interspersed through out the cipher. A curious explanation of the process of unraveling a cipher is given in Poe's story of the (Gold-Bug.' Still, with devices such as these, more or less ingenious, the world was fain to be content until the advent of telegraphy. Immediately a new want made
itself felt. If the mail was slow, it afforded privacy, but the contents of a telegraphic mes sage are of necessity known to others besides the sender and the receiver. So the minister, the banker and the merchant soon began to send cipher despatches. It was quickly discov ered, however, that existing methods of cipher writing were unadapted to telegraphy; the costliness of the new invention necessitated brevity; and thus it was not long before there went whirling over the wire messages of 10 words that, properly deciphered, included from 30 to 50. Cryptography became a recognized calling, requiring thought, labor and inventive skill. A great proportion of commercial mes sages — orders to buy and sell and the like— are similar in their terms, and hence it is that a single word representing three or four words in frequent use is the plan on which our present cable ciphers are based, whereby there is annu ally a large saving in expense. Then, too, as trade increased and competition became fierce, every firm wanted or needed its own cipher sys tem, distinct from any other. Hence there is a vast number of ciphers in use in every great commercial centre such as New York or Lon don. There are firms which specialize in the preparation of ciphers or "cable codes* contain ing from 50 to many thousands of words. The International Office of the Telegraph Adminis trations in Bern, Switzerland, published an "Official Vocabulary for Telegrams in Precon certed Language* (1899-1901). In 1903, how ever, it was internationally decided that, after July 1904, all combinations of letters that do not exceed 10 will pass as one cipher word, "provided that it is pronounceable, or that it is taken from the following languages: English, French, German, Dutch, Spanish, Portuguese or Latin.* This concession widened enor mously the scope of admissible words and huge, complicated codes sprang into existence. From the volume issued by the Lieber Code, for instance, it is claimed that 100,000,000 combina tion ciphers can be devised. The "Simplex Cryptograph* (Providence, R. I., 1902) is a small book, giving over 50,000 numbered cipher words with a "key') to each one. In this, e.g., the number 33,458 can be expressed by the word "post,* and 50,551 by the word "vary.* The cipher codes of the State Department at. Washington and those of other governments are frequently changed. The special code is entrusted to the personal custody of diplomatic officials embarking on a mission, who retain possession of it and destroy it if their lives are endangered. The imprisonment of the United States Minister Conger, in Peking, in 1900, caused the cipher to figure conspicuously in in ternational relations. China objected to the transmission of cipher dispatches, but subse quently withdrew her objection. She was ac cused of having obtained surreptitious posses sion of a copy of the United States cipher code.