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From FLYNN's February 21, 1925


Edited by M. E. Ohaver

INTEREST in FLYNN'S cipher department, amazingly large as it was on its first appearance, has grown a thousand-fold on the appearance of the second article.

We wish you could see the piles and piles of letters containing the solutions of our readers. It is a heartening thing to observe the numbers of persons who, with no other incentive than their own personal satisfaction, are turning their wits to FLYNN'S cipher department.

We are doing all we can to make its appearance an event in homes where FLYNN'S is a weekly adventure.

N earlier times the simplest cipher systems were usually proof against unauthorized translation by persons not in possession of the key. The earliest known methods of secret writing date back to about 500 B.C. But successful attempts at deciphering without the key were probably not made until a much later date.

Indeed, the first work of the kind known to have been written is by Sicco Simonetti, dated 1474 A.D. If any of my readers believe in thirteen as an unlucky number, let them beware of this work by Simonetti, for it contains just thirteen rules to assist in the deciphering of cryptograms.

At length came the discovery that all the letters of the alphabet were not used in equal numbers. And this seemingly insignificant fact was full of startling possibilities for cryptographers.

Alphabetical lists were prepared in which the letters were arranged in the order of their frequencies. Such a frequency table is here given:


It will be seen that "E" heads the list as the most frequent letter. "T" comes next, and so on down the line to K-X-J-Q-Z, which are used least of all. The letter "E," however, usually outnumbers any others by a safe margin. If the cipher enthusiast will take time to scan almost any line of reading matter, he will find that, in fact, this letter does actually predominate.

You are already familiar with transposition and null ciphers from previous issues. For this week's problem we will select one of the substitution class. In ciphers of this type the letters retain their original order, but are represented by substitutes, that is, by figures, signs, or other letters. For example, suppose it is arranged to represent each letter by the letter next before it in the alphabet. Thus A would be written in place of B; B in place of C, and so on.

A system of the type just mentioned is called a methodized-alphabet cipher, because the substitution is according to a uniform plan. In such a cipher as is mentioned above, the discovery of a single letter leads to the discovery of all the others, because all the substitutes are determined by the same rule. This week's cryptogram is one of this type.

To solve it you must first prepare a list showing how many times each cipher character occurs. The character occurring the greatest number of times will represent "E." By noting what relation this cipher character bears to "E," and applying the same rule to all the other letters, the message can be read without any great difficulty.

To assist the learner, we will show just how to prepare a frequency table of the cipher characters. First, write down the twenty-six letters of the alphabet. Then, beginning with the first letter in the cipher, place a mark to the right of a letter on your table each time that letter is used in the cipher.

The frequency table given herewith is for this week's cipher, which has, by the way, a renowned history.

A-   0
B- 3
C-   0
D- 2
E- 2
F- 14
G- 2
H-   0
I- 3
J- 3
K-   0
L-   0
M- 3
N- 3
O- 4
P- 4
Q-   0
R-   0
S- 6
T- 4
U- 8
V- 1
W- 1
X- 2
Y-   0
Z-   0
Total ---------- 68

It was used by no less a personage than Augustus Caesar, Roman emperor, nearly two thousand years ago. This system, and also that of Julius Caesar, which we will print in an early issue, completely baffled any attempts at solution for centuries.

These ciphers were still in use up to the time of Sixtus IV (1471-1484 A.D.), when their secret was divulged by Leon Battista Alberti, and a new sort of cipher sprang up. But we venture to say that if you have carefully studied the cryptographic principles outlined above, you will need but a few minutes to decipher the following cryptogram, which is written in the Augustus cipher.



We were glad to note how alert our readers were in seizing the bit of a clew we threw off regarding the punctuation in the Trevanion cipher, which appeared in FLYNN'S for January 17.

That little suggestion helped many through to victory.

The correct solution read: Panel at east end of chapel slides. Every third letter after a punctuation mark was a letter of the message. We reprint this cipher below with the "significants" in italics;


Hope, that is ye beste comfort of ye afflicted, cannot much, I fear me, help you now. That I would saye to you, is this only: if ever I may be able to requite that I do owe you, stand not upon asking me. 'T is not much I can do: but what I can do, bee you verie sure I wille. I knowe that, if dethe comes, if ordinary men fear it, it frights not you, accounting it for a high honour, to have such a rewarde of your loyalty. Pray yet that you may be spared this soe bitter, cup, I fear not that you will grudge any sufferings; only if bie submission you can turn them away, 't is the part of a wise man. Tell me, an if you can, to do for you any thinge that you wolde have done. The general goes back on Wednesday. Restinge your servant to command.

R. T.

The First Week's Grist

Within a week after the appearance of the Trevanion cipher these persons had submitted correct solutions. They have come from towns scattered clear across the continent and ranging from Canada to the Culf States. Evidently cipher enthusiasts are as widely distributed as cross-word puzzle experts. Is your name in the list?

Watch these pages for the next appearance of this department.

We promise you some interesting facts about that remarkable system of communication known as the "prison telegraph."

Very soon we are going to swamp you with a few challenge ciphers sent in by readers who challenge the world to solve them. They'll give you a merry tussle.