Secret Writing.

Woodville Examiner, Volume 3, Issue 284, 17 September 1886, Page 2 (Supplement)

Secret Writing.

Years ago cryptography was a favorite study; and, considering that—apart from other considerations —it is an excellent mental exercise, this is by no means surprising. There was, at one time, a skilled decipherer of cryptograms attached to the office of the Minister for Foreign Affairs, and, for anything we know to the contrary, there may be now. The great object of cryptograms is that the moaning you wish to convey shall be intelligible to those only for whom you intend your message. To note all the ingenious methods invented to this end is beyond our power. We will, however, refer to the most noteworthy. One of the easiest methods of cryptography—which was known to the Greeks—may be illustrated as follows : 123 4 5 afl g v 1 bgm r w 2 chn s x 3 dio t y 4 e k p u zls The method of using it is this. Supposing 1 Take care ’’ was the message to the transmitter, The cipher would run thus—“ 44, 11, 25, 15, 13, 11,42, 15.” It will be seen that every letter is represented by two figures—the one at the top of the column in which the letter is and the one at the side, as “a 11.” The great drawbacks of this cipher—and, indeed, of many others —are that it is too easy to read, and that it could not fail to excite the suspicion of anyone into whose hands it fell. Another very simple method of ciphering is to use, instead of each letter of the alphabet, a certain other letter. For instance, z for a, y for 5, x for c, and so on. Or figures my be used, as 1 for a, or 2 for b. Both these methods, however, as we shall explain, are easily deciphered. At one time there was in vogue a system which consisted of writing a sentence in good English, with the intention that only a few words should convey the desired meaning. One of the cryptograpers gives this sentence as a specimen : “ I shall be much obliged to you, as reading alone engages my attention, if you will lend me one of the eight volumes of the Spectator. ” By the aid of this cine the recipient picks out the words : “ I shall be . . . alone . . . at . , . eight.” Tlie great beauty of this system is that its wording does not excite suspicion. A good mode is to obtain two copies of a scarce dictionary—the scarcer the better—one copy of which must be in the possession of the sender of a message and the other in that of the receiver. The mode of use is this : Having written down ycur message, take the number of the dictionary page in which the first word occurs and also the number of lines from the top, as say, “ 3G5, 15,” You may go on thus until the message is completed, without the least fear ot anyone (except the proper person) deciphering it. In attempting to decipher a cryptogram, the first thing to do is to find if it is written in English. If so, a mere counting of letters or signs will show what stands for e, and the rest is comparatively easy—that is, if every sign represents only one letter. Sometimes, however, one sign is made to represent two, three, four, five, or even six letters. Then the task of deciphering any cryptogram is, of course, considerably harder. It should be noted, too, that often no division is made between words, and sometimes, in order to baffie the decipherer, false divisions are made. If any character is by itself in a cryptogram, and the proper divisions between words have been observed, it must stand for either a or *— that is, if the cryptogram be written in English—and, therefore, the decipherer has ai once two very important clues. Sometimes the message is inverted, as, for instance, “ I love you ” —“ uoy ovol I”—and then turned into cipher, in which case it is much more baffling to a decipherer. One of the cryptograms submitted to Poe had for its key-note the Latin quotation, “ Suaviter in modo, fortiter in re which would be arranged thus— SUAVITER IN MODO, FORTITER IN RE. abed efgh ij klmn opqrstuv wx yz. It will be seen that there are as many letters in the key phrase as in the alphabet, and that some letters occur several times. I stands for e, i, s, w ; t for fr ) t; e for g, u, z ; r for h, q, v, y; o for I, n, p. Therefore, the task of deciphering any ciphers written by this method, as we have stated before, is much more difficult. To show how easily a simple cryptogram can be deciphered, we will give an example. A short time ago there appeared in the “agony column” of one of the London dailies the following advertisement:— “ Cousin,— S2L4P7 ETLD 54T HSD 3TBBTD VLB a 59 358 RLFT 21R 8214 P I QT4B 82TDT HSD 75RT 54T T37T ? 714 A 85R5DD5Q L 8 ST4 OLVP 2TDT T3Th T 4 821D8a ASE 03T77 a 59 ELD3I4A I 35&T a 59 QLSVTE 82DTT 259D7 85ELa.” Commenting on this advertisement the Standard observed that a mere counting of the most frequent letters showed that “T” stands for e. The Standard continues: “ The last word but two ends with a double e. Few short English words do so, and in most of those an r precedes the doublet. So ‘B2DTT’ might be ‘spree,” or ‘ three.’ If it be the latter we shall find the ‘ 82 ’ elsewhere, as ‘th ’ is a very common combination of letters. As it occurs five times, we may assume it. We have now four most important letters, and we know that “D" stands for r. Looking to the early part of the line above, we find the word ‘ 85R5DD5Q.’ The word has a doubled r, with the same letter preceding and following , it. Such a letter must be a vowel, and can only be an o, giving us for the word ‘to-orro.” Of course this is * to-morrow,’ and by applying our knowledge to the next two words, we find that they must mean "at ten.’ With this start, any person of ordinary intelligence will make only five minutes’ work of the rest of the cipher.” A little reflection will show our readers that the advertisement reads as follows: — “Cousin, —Thanks, dear one, for your letter. Can you not make him think I went there for some one else ? Back here eleventhirty. God bless you, darling, I love you. Waited three hours to-day.” This ought to be a warning to sentimental lovers, who should understand that such a cryptogram as the one which we have quoted is very easy to decipher, and mere child’s play to anyone who understands the rules which we have mentioned. The only safe plans are to employ what is known as the “dictionary method,” or to substitute one word for another; then the most skilful cryptographer may he almost defied to discover your meaning. One or two mechanical arrangements have been invented to render deciphering impossible except by those initiated; but they are far too complex to describe in the columns of Tit-Bits,