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From FLYNN's May 28, 1927


Edited by M. E. Ohaver
  P RS V R   Y    P RF CT  M N
V R  K  P  TH S    PR C PTS  T N

T HIS inscription, say the puzzle books, is to be found over the entrance to an ancient and historic monastery in England.

As the story goes, it was originally painted in two colors; the consonants being in black, and the vowels, of which only E is used, in red. And it is said that the red letters faded out, leaving the string of irregularly spaced consonants to perplex the curious.

The inscription is so well known that it is unnecessary to append its translation. But speaking of " precepts," our own list of the essentials of cipher composition, announced in this issue of March 26, has, through the unavoidable pressure of more urgent material, been temporarily sidetracked, but by no means overlooked or forgotten.

And after due consideration, it seems advisable to present the entire series at once, leaving the discussion of the individual statements for subsequent issues.

Here, then, are ten standards by which it may be well to measure the relative merit of a cipher system:

  1. A cipher should employ symbols that are easy to write, read, and pronounce, and that are transmissible by existing modes of communication.
  2. It should express a given message in the shortest practicable cryptogram.
  3. Its security or use should not be dependent upon any limitations in the text of the message material.
  4. It should permit easy and rapid encipherment and decipherment, and by one'or more persons.
  5. Any rules, tables, books, apparatus, machines, or other equipment which it might employ, should not render it impracticable for its intended purpose.
  6. It should be capable of a practically unlimited number of variations, securable by keys which are easy to remember, change, and communicate.
  7. Without the keys, any number of cryptograms in the same or different keys should be absolutely undecipherable, even with full knowledge of the system and possession of the necessary apparatus.
  8. Any comparison of one or more cryptograms with all or part of their translations, or with their encipherments in other systems, should not lead to any further decipherment.
  9. With the key, method, and equipment, the cipher should be capable of only one interpretation.
  10. If required, it should lend itself to use without suspicion.

The first of these propositions has already been discussed in the March 12 issue; and others will be considered in forthcoming installments, beginning next week.

In the meantime we should be glad to hear from our reader on the subject. It is believed that these propositions cover the ground. But some points of more or less importance may have been overlooked; and suggestions, additions, or criticisms are invited.

L. H. P., Chicago, has written us interestingly about his solutions of the Blair ciphers—see FLYNN'S WEEKLY for July 25 and August 15, 1925—inquiring also if a certain other cipher, propounded by Blair, has ever been explained.

The cipher in question was published by Blair with its translation in his cipher article in Rees's Cyclopaidia, but without any suggestion as to the method involved. However, Blair did not claim any particular advantages for the system, offering it more on account of its somewhat remarkable appearance of an unknown language.

Incidentally, this cipher fails to meet the requirements of propositions 2, 7, and 8, herewith. For the cryptogram is more than twice as long as the message it conveys; it is decipherable without the key; and it can be readily matched up with its translation.

Nevertheless, it should afford an interesting half hour's study. Certain errors in the original have been corrected here by using symbols found elsewhere in the cryptogram.

CIPHER No. 23 (William Blair).

Cryptogram: Sika jygara a fuva quaxo
Rolofak adunabi ye, Rase quema Lovazig
arodi; Moxati Ho hyka Fagiva myne quidoxo
Aukava in Onfa yani moxarico, Pangdo
Spulza Jorilorixa mugaro ya zaspor Alsiva
yival ponbine Kazeb re linthvath.

Translation: Relieve us speedily, or we perish; for the enemy has been recnforced, and our provisions are nearly expended.

"To exercise the English scholar" Blair also offers the following example of "plain ciphering," without the key or translation. This cipher employs a methodized alphabet, in which each number fixedly signifies but one letter. Can you read the message, and reconstruct the alphabet?

CIPHER No. 24 (William Blair).

39.  38,31,21,35.  35,14,20,18,21,19,20,35,
34.  20,38,39,19.  32,35,31,18,35,18.  22,
39,20,38.  13,31,14,24.  20,38,39,14,37,
19.  31,19.  20,15.  20,38,35.  13,31,14,31,
37,39,14,37.  15,36.  20,38,35.  31,36,36,
31,39,18.  18,35,17,21,39,19,39,20,35.
36,15,18.  24,15,21.  20,15.  11,14,15,22.
18,35,13,35,13,32,35,18. 20,38,31,20.
15,14.  14,15.  31,33,33,15,21,14,20.  24,
15,21.  36,31,39,13.  20,15.  13,35,35,20.
13,35.  31,20.  14,39,14,35.  20,15,13,15,
18,18,15,22,19.  14,39,37,38,20.  36,15,
18.  22,35.  13,21,19,20.  14,15,20.  14,
15,22.  34,35,12,31,24.  20,38,35.  19,21,
18,16,18,39,25,35.  15,36.  20,38,35.  33,
31,19,20,12,35.  22,38,35,14.   20,38,39,
14,37,19.  31,18,35.  39,21,19,20.  18,39,
16,35.  36,15,18.  35,23,35,33,21,20,39,

The translation of cipher No. 21, published last week, is as follows: " The crypt is a form of cipher employing a method of simple literal substitution."With its common, short words this should have been easy. Did you get it?

The two-alphabet principle involved in the autokey method outlined last week, and published here for the first time, can be used effectively against other important types of autokey ciphers, as we may later have opportunity to demonstrate. The recurrent group 27-27-31-11, at the interval 13, was a ready clew in last week's example. No. 22, which used a reversed 26=A ... 1=Z alphabet. The message: "There is a skeleton in every house, and every family of respectability has its family ghost."

Coming now to the code messages published in the April 23 issue. No. 1 conveyed the following information enciphered with the key, 05175 49915 34073:

The crew of a Cantonese (Canton -ese) gunboat (gun boat) rebelled to-day and shelled Shanghai while attempting to bombard the arsenal one mile south of the city.

Code message No. 2, as follows, was enciphered with the key 12052:

We have discovered an underground (under ground) vault near the center of the island filled with pirates' treasure.

Each two-letter syllable in No. 3 represented two figures according to the followi ng table, where MU, for example, equals 4g (45 plus 4); and so on.

             00 05 10 15 20 25 30 35
Consonants:   B  C  D  F  G  H  J  K

40 45 50 55 60 65 70 75 80 85 90 95
L  M  N  P  R  S  T  V  W  X  Y  Z
               00 01 02 03 04
Vowels:        A  E  I  O  U

Translating the code words into code numbers, 49915 34428 09955 ... and these, in turn, into their proper vocabulary terms, reveals the message: "United Products has declared the regular quarterly dividend of two dollars."

Challenge cipher No. 12 (Fletcher Pratt), published in the issue of April 16, used the figures 2 and 3 for A; 4 and 5 for E; and 6, 7, 8, 9, for the word-space. Any other letter was represented by the three letters next following it in the alphabet, and by itself, according to its occurrence in the message.

Thus, O is substitute for the first L in the message; N, for the second L; M, for the third; and L itself for the fourth; this order being repeated 'as many times as necessary. Here is a sample of the encipherment, and its translation in full:

S4UVR  Q3ONB  6L6IK  PG9WK ...

Personally I find the work of solving cryptograms insuperable; but I. enjoy designing them, and flatter myself that this one will offer such difficulty to your solvers that none will earn the year's subscription to FLYNN'S I will give to the first who succeeds in doing so.

This cipher should be subject to resolution by the use of alphabetical strips, or by "running down the alphabet"—see FLYNN'S WEEKLY for November 13, 1926—determining the values of the figures by context. Should any award be made in this instance, it will be in favor of the best solution submitted, as advised in the issue of April 16, instead of the first solution, as stated in the cryptogram.

The following have submitted answers to the first five of the weekly department ciphers, published in the issues of March 5, 12, and 19:

That's it, folks! Keep the answers coming. The more, the merrier! And while you're at it, send along that cipher of yours—preferably with the solution—for other readers of the department to puzzle over.

As a bit of advice on parting, don't fail to see next week's department. Among other things you will find in it some new ciphers, and the full explanations to the Blair ciphers in this issue.