book cover
From FLYNN's June 9, 1928


Edited by M. E. Ohaver
An Interesting Explanation Accompanies the Solution to the Le-
grand Open Letter Cipher of Last Week
—With the Other Features

IN the Legrand open-letter cipher, of which last week's Cipher No. 181 was an example, either a key word or a date may be used by the corresponding parties in determining their numerical key.

If a date is used, the month is merely replaced by its number in the year, the remaining figures being unchanged. October 12, 1492, for example, would give the numerical key 10121492. If a word is employed, the letters are replaced by numbers, 1 for A, 2 for B, and so on. In this way the word CRYPT, for example, would give the numerical key 318251620.

Cipher No. 181 used the numerical key 920, derived from the key word IT, and conveyed the following message : "Send report at once to agreed address."

To decipher this example with the key, number the words of the external message from 0 to 9, repeating the series as many times as required by the length of the cipher. The words of the internal or real message will then fall, in rotation, under the numbers 9, 2, and 0, as shown in italics herewith.

To encipher a message in this system, write out the series of figures, place the significant words under the proper figures as determined by the numerical key, and fill the intervals, one word for each figure, with nonsignificant words so that the whole will convey another meaning. Contractions are given a count for each word in them. Salutations, signatures, and so forth, are not counted.

  0    1     2   3   4        5
Many thanks for the very interesting
   6      7    8   9   0    1
puzzles which you send me. Will
  2    3   4     5      6  7   8
report on them later, haven't time
  9  0     1    2   3   4     5   6
just at present to try them. Saw one
7    8   9     0      1   2   3
of them once before. Hope to hear
 4    5    6    7       8       9
from you every week; remember, you
   0   1    2     3      4   5   6
agreed to write often. Until I advise
 7      8         9    0   1
you otherwise, address me here.

This system was devised to avoid certain defects which exist in the well-known word grille cipher. In the latter the corresponding parties provide themselves with exactly similar grilles, or cards pierced with small rectangular openings, through which the words of the secret message are written, the intervals afterward being filled in with nonsignificant words so that the whole communication will, as in the Legrand system, convey a different meaning from that actually intended.

In Legrand's cipher, the numerical key supplants the openings of the word grille in regulating the locations of the significant words. This not only avoids unnatural crowding and spreading in the lines, but also permits the communication to be sent by telegraph, telephone, et cetera, just as well as by letter.

It is a rather difficult matter, however, to compose the external letter in either of these systems so that undue emphasis will not be placed on the significant words. And this very fact can, of course, be put to advantage in deciphering without the key.

In solving without the key, it is also a good plan to write the cryptogram in lines of ten words each, forming ten columns. All the words in any given column will then have the same key figure, and favorable combinations in any part of the cipher can be quickly tried in other lines, thus gradually developing the whole key. For similar reasons, solution is much easier when several messages in the same key are available.

Cipher No. 184, in this article, is another problem in the Legrand system. As a final detail of this system we might mention that Legrand also proposes numbering the words from 9 to 0, if desired, instead of from 0 to 9. But we shall leave the reader to find for himself whether the ascending or descending series has been used.

Last week's crypt No. 179, by J. Lloyd Hood, conveyed this interesting bit of information: "Pious Jews wore a phylactery, small square box, upon forehead also left wrist." Solution here could have begun by comparison and analysis of the groups I (a), EDIVV (small), and IVEA (also). A fine crypt, this!

T. H. Gillespie's No. 180 was a very clever multiple alphabet system employi ng a straight A-to-Z alphabet in which a backward count was used for letters in the first half of a word, and a forward count for the second half.

These counts were further regulated by the distance of the letter from the center of the word, 1 being used for letters next to the center, 2 for those second from the center, and so on. Central letters in words having an odd number of letters were enciphered as they stood.

'The translation in full is as follows: "Here's one the very simplicity of which makes it a difficult one to untangle. Am I not right my friends?" The following short example will illustrate the method of encipherment:

Key:      21012 212 212 2112 ...
Message:  HERES ONE THE VERY ...
Cipher:   FDRFU NNF SHF TDSA ...

Our readers have been sending in some good crypts lately. Don't be afraid of the long words. Roll up your sleeves, and jump right in !

We don't want to tell you too much about No. 183. But we will say that it uses two cipher letters for each message letter.

All right, ladies and gents, up and at 'em! Remember, another solvers' list will be published before long. So send in your answers from week to week. Also your new ciphers. Answers to this week's ciphers will appear in the next issue.

CIPHER No. 182, by M. Walker, Akron, Ohio.


CIPHER No. 183, by Irving Bloom, Brooklyn, New York.


CIPHER No. 184.

  We have not heard from Williams; please
wire when everything is ready. Have deposited
money in bank and can start on the
job at once.
  Will hold ourselves in readiness to go ahead
pending receipt of wire. Can be through by
Monday if we start now.
              Very truly yours.