HIS week's festivities will be initiated by the promised explanation of cipher No. 1 (Kenneth Davidson), published in the March 5 issue, for the best correct solution of which Mr. Davidson offered a year's subscription to FLYNN'S WEEKLY.
Mr. Davidson has here an ingenious and efficient cipher of a double substitution type, employing the Bacon biliteral alphabet—see FLYNN'S WEEKLY for April 25, 1925— and the International Morse telegraph alphabet—issue of September 4, 1926.
The cipher involves a letter fragmentation process which is perhaps best understood with the alphabets arranged as below, where the Morse dots and dashes have been discarded in favor of a's and h's, in conformity with the Baconian alphabet. Observe that the Bacon symbols for I-J, and for U-V, are identical.
(Bacon) (Morse) (Bacon) (Morse) aaaaa A ab abbaa N ba aaaab B baaa abbab O bbb aaaba C baba abbba P abba aaabb D baa abbbb Q bbab aabaa E a baaaa R aba aabab F aaba baaab S aaa aabba G bba baaba T b aabbb H aaaa baabb U aab abaaa I aa baabb V aaab abaaa J abbb babaa w abb abaab K bab babab X baab ababa L abaa babba Y babb ababb M bb babbb Z bbaa
The encipherment of a message (a), is accomplished by first replacing the letters, as at (b), with their proper Baconian equivalents. These latter are then regrouped as desired, at (c), into Morse symbols, for which are substituted, at (d), the corresponding letters in the Morse alphabet. The resultant series in the conventional five letter grouping (e) constitutes the cryptogram.
(a) G I V E N ... (b) aabba abaaa baabb aabaa abbaa ... (c) aab baab aaab aa bbaa baaa b baa ... (d) V X V I Z B T D ... (e) UXVIZ BTD—— ...
Decipherment of a cryptogram is merely a reversal of the process just recited. The full translation' of this cryptogram is : "Given sufficient time any cipher can be made to yield its secret. Can you do it?"
A given message, depending on the regrouping, can assume in this system many different forms in cipher; and the cipher can be modified for individual use by changing either or both alphabets from their original order. Results on this cipher, from the contestant viewpoint, will be noted in an early issue.
This week our readers are again coming to the fore with two interesting cryptograms.
The first, and easier, example is a straight substitution cipher, using an alphabet of biformed letters. Fragmentation plays an important role in the second, which illustrates a novel and surprising use of Bacon's biliteral alphabet.
CIPHER No. 8 (Basil. Condon, Durham, N. C).
rocRR NPsVg CITSR RPsgC PnosI gCIlc ORPLh SnSTS tIVgo pPIhg CIVIe gIiPg roNgC IHcGR RJi.
CIPHER No. 9 (J. Levine, Los Angeles, Calif.).
11112 21324 11121 71722 17121 33513 13133 11411 14361 32411 12171 41212 21122 22111 14221 21332 15251 5121.
A discussion of Nos. 6 and 7, last week's ciphers, is next in order and will follow immediately.
No 6 (Dr. G. A. Ferrell) conveyed the message: "Here is an easy challenge cipher; it is not undecipherable, but it will tease a bit. "The message was enciphered by transcribing it in lines of 1, 2, 3, 4-— letters, in triangular form, as shown herewith. The transposition was completed by taking the columns downward, from left to right, in groups of five: HEEAS LCTDB LRINY, et cetera.
H E R E I S A N E A S Y C H A L L E N G E C I P H E R I T I S N O T U N D E C I P H E R A B L E B U T I T W I L L T E A S E A B I T
This form of triangle transposition cipher is easy to use, a letter count being unnecessary in either encipherment or decipherment. Thus, to decipher the present example h is only required to transcribe the cryptogram backward, in columns of 1, 2, 3—letters, written upward, and from right to left.
The cipher is also easy to decipher without the key. It can be recognized as a transposition cipher by the vowel test, given in full in FLYNN'S WEEKLY for October 2, 1926. Further, in transpositions of this pattern, the lines increase by a constant difference, and the whole numbers of letters constitute a series of figurate numbers, as follows:
(Arithmetical Series) 1 2 3 4 5 6 7 8 9 10 11 12 ... 1 3 6 10 15 21 28 36 45 55 66 78 ... (Triangular Numbers) *
The sixty-six letters of the cryptogram thus suggest the possibility of a triangular form. This is further borne out, and the order of transposition is discovered by the following treatment of the final letters of the cryptogram; a continuation of which would readily develop "... TEASE A BIT," the last words of the message.
... E I E N R T A A W B I I T ... 4 3 2 1 0
Cipher No. 7 (Francis A. Gauntt), which is similar to the Radio Cipher analyzed in the December 18, 1926, issue of this magazine, uses the following methodized alphabet.
0 9 8 7 6 1 A B C D E 2 F G H I J 3 K L M N O 4 P Q R S T 5 UV W X Y Z
The key was "F. A. G." (20-10-29), and the message: "Poe may have been right, but I would hate to be called upon to prove it."
Speaking of the Radio Cipher, an additional entry, correct in every detail, and dated November 27, 1926, was submitted by E. H. Barber, lieutenant commander (SC), United States Naval Station, Cavite, Philippine Islands; but was received too late for listing in the January 22 issue.
We regret that the one month time limit prevented the consideration of this entry, and shall endeavor to frame any future contest, where such a valuable prize is involved, so that all comers, however distant, shall have an equal chance. Lieutenant Commander Barber also sent along correct solutions to October 2 ciphers Nos. 1 and 2.
As a parting word, don't fail to see next week's FLYNN'S WEEKLY. Besides the answers to the ciphers in this issue, and some cryptograms for you to solve, it will contain a curious find by one of our readers.
Don't miss it!