THE purpose of an open letter cipher, such as last week's problem No. 178, is to convey a secret message without seeming to do so.
Grandpré's system, used in preparing problem No. 178, is a combination.substitution-null cipher of this class, based on the Grandpré ten by ten word square alphabet described last week.
To translate this cipher, count the number of letters in every fourth word of the external communication. Then, dropping tens figures, if any, pair off the units figures by twos, and find the letter equivalents of the resulting numbers in the alphabetical key square.
In counting every fourth word, all words forming contractions and hyphenated compounds are counted individually. And the count runs continuously through the body of the communication, unbroken by punctuation or paragraphing. But the date, salutation, signature, and so forth, are excluded.
In counting the letters in every fourth word so selected, any contracted word is given its full number of letters. Words of from one to nine letters are given their regular count. Ten-letter words are counted as 0; eleven-letter words as 1; twelve-letter words as 2; and so on.
Cipher No. 178, reprinted below with every fourth word in italics, will serve to illustrate this procedure. Note that "I'm," "twenty-ninth," and so on, are each counted as two words; and that the second word of the contraction "I' m" is counted as a two-letter word.
May 26, 1928. DEAR JOHN: Your last letter reached me today. Will answer immediately, as I'm (I am) leav- ing on the twenty-ninth for several days. Will write you again upon my return, not later than the last of next week. Nothing of any importance here to tell you about. Everything is just as usual. Can't (Can not) say how much longer I'll (I will) stay here. Three or four more weeks anyway. Must stop writing now, so good-bye. PHIL
Counting the letters in the italicized words in this example, and pairing off, we obtain the numerical cipher: 76-26-45-34-74-52-31-55-73. Substitute now for these numbers from the key given last week, 76=S, 26=T, et cetera, and we have the message: "Strike now."
Last week's crypt. No. 176, you will remember, was signed with the alias, "Edward Pommeth, Pinwig, Tenn." Did you succeed in discovering friend "Pommeth's" real identity? Here is the answer: "Came Thursday, leave today. Your pal. Arthur Bellamy, Boston, Mass."
To read Dr. Ferrell's transposition cipher, No. 177, transcribe it by successive horizontals, left to right, into the subjoined triangle. Then take by descending verticals, left to right, and get the message: "Flynn's is the best magazine published, and Solving Cipher Secrets helps make it the best of all."
F L N I E M N S O H H T Y N S B A E H L E E H S T E G P E V R L E H S A U D I S P B T Z B A N E S E I L N G C M S I D C R A T S I E K O P T E F S I A T L L
Now try this week's ciphers. No. 179 is a crypt, or straight substitution cipher, not extremely difficult, but plenty, hard enough to be interesting. If you solve it, let us know what words gave you your start.
Aside from saying that No. 180 is not a simple substitution cipher, we won't offer any hints as to its solution. Mr. Gillespie would like to know how long it takes you to solve his problem. Get busy and see what you can do with it.
Problem No. 181, like No. 178, is another cipher of the open-letter type. This system is also of French origin, having been devised by Dr. Max-Albert Legrand, and described in his booklet, "Le Krypt."
In the present case a short key has purposely been used so that this fact may be taken advantage of in solving. This is a rather stiff problem. But give it a trial, and let us know what luck you have. Answers and full explanations to all of this week's ciphers will be published next week, including full instructions for using the Legrand cipher.
CIPHER No. 179, by J. Lloyd Hood, Bastrop, Texas.
GRACE MUSE SAKU I GLYVIZ- NUKY, EDIVV EXCIKU HAW, CGAB PAKULUIT IVEA VUPN SKREN.
CIPHER No. 180, by T. H. Gillespie, La Junta, Colorado.
FDRFU NNF SHF TDSA NEJNK- JELXD NG UGIDJ KZKFU HU A ZFDEIDWOX NNF SP QKRZOIOI ZN I MOU PHGIV LZ CPHEOFV.
CIPHER No. 181.
DEAR FRIEND: Many thanks for the very interesting puzzles which you send me. Will report on them later, haven't time just at present to try them. Saw one of them once before. Hope to hear from you every week; re- member, you agreed to write often. Until I advise you otherwise, address me here. Hastily yours, "X."
The following solutions have been received to Ciphers Nos. 1299 to 151, inclusive. Names are listed alphabetically according to the number of answers submitted. Messrs. Bellamy and Boyer occupy first place with seven answers each to their credit. Four other fans have four answers each; and so on down the line.
Our next solvers' list will be published in a few weeks. A single answer will put your name on it, but send in as many as you can get. Swell the list of solvers!