book cover
From FLYNN's April 24, 1926

SOLVING CIPHER SECRETS

Edited by M. E. Ohaver
HERE IS AN INTERESTING DISCUSSION ABOUT THE WORK OF
ONE OF THE FATHERS OF CRYPTOGRAPHY, AENEAS TACTICUS

HE origin of cipher writing is lost in the mists of buried centuries.

The early history of the subject is very fragmentary, and the information to be had from the relatively few and widely scattered records that have survived, does not point to any certain time or place as marking the beginning of the art.

However, taking those ciphers known to have been used as fairly representative of contemporary systems, it is possible to form some idea of cipher writing as practiced by the ancients, and a conception of the progress reached in cryptography in these early times.

The Lacedæmonian Scytale—described in the first article of this series in FLYNN'S, for December 13, 1924—is one of the first ciphers of which there exists any record, it having been used in the fifth century, B.C.

And one of the first writers known to have enumerated and described various methods of secret writing was the Greek author, Æneas Tacticus, of the fourth century, B.C., who, according to Polybius— Greek historian of the second century B.C.—collected together about twenty different modes of writing not understood by any but those in the secret, some of which were original with Æneas, the rest being the inventions of others.

Æneas was one of the first to write on war tactics, and his treatises on the subject are mentioned by Polybius, and by another ancient Greek tactician and author, Ælianus Tacticus.

Unfortunately, with the single exception of a short Greek work generally attributed to Æneas as having been written about the middle of the fourth century, B.C, dealing with methods of attack and defense of strongholds, all of this author's works are lost. And with them are lost all of his ciphers, excepting what may have been described in this short work, and what has been mentioned by Polybius.

The several methods of secret communication thus so fortunately preserved will be treated in this article, where they are grouped into three classes: a military telegraph; methods of concealment; and systems of secret writing, or ciphers proper.

The telegraph of Æneas, as described by Polybius, was a visual method of transmitting messages relative to the common events of war. The stations, both of which were equipped with exactly similar pieces of apparatus consisting of earthen vessels, supplied with cork floats, could be at any distance apart within sight of each other, and communication was effected by means of torches, or other lights.

The vessels, made to contain water, were exactly alike in all their dimensions, and were fitted with spouts or cocks, also of ihe same size, so that when both were opened the water would be discharged from the two vessels at exactly the same rate.

The floats were made to rest upon the water within the vessels, and each of them supported a perpendicular stem marked longitudinally into several parts, upon each of which divisions could be written a sentence, as, for instance: The enemy is advancing. Send reinforcements. The enemy has been repulsed; and so on.

To use the telegraph, the vessels were filled to the same height with water, and the floats were placed in position.

Then the operator at the sending station raised a torch, and continued to hold it aloft until a torch was raised in like manner by the operator at the receiving station, who thus informed the sender that he was ready.

The second operator then lowered or removed his torch, at which instant each operator opened the cock of his vessel, allowing the water to escape, and the cork floats to descend.

When the sending operator observed that the division bearing the intended message on the floating stem had fallen to a level with the mouth of his vessel, he immediately raised his torch again, whereupon both operators shut the cocks of their vessels simultaneously.

Since the cocks would thus have been opened the same length of time, the water would have subsided equally in both vessels, and the floats would have fallen through equal vertical distances, with the result that the mouths of the two vessels would now be at a level with identical divisions on both stems.

Consequently the receiving operator needed only to read the message so indicated on the stem of his float to be in possession of the intelligence the sending operator had desired to transmit.

The Æneas telegraph was necessarily limited in use to the messages previously inscribed on the stems. And in this sense it is inferior to the later telegraph invented by Polybius himself—see FLYNN'S for March 28, 1925—by which it was possible to communicate alphabetically.

Nevertheless, the Æneas telegraph contains the germ idea of the modem telegraphic code. or in the latter, the words or phrases of the message are first replaced by groups of letters or figures, which are converted into dots and dashes for telegraphic transmission by any method, as for instance by the light flashes of the heliograph; while in the former the several messages on the stems are represented by certain volumes of water, converted by the apparatus into intervals of time, these being transmitted as light signals.

In the Æneas telegraph any message could thus be just as well represented by a number—comparable to the modem code group—signifying the amount of water required for that message in a given unit of measurement.

As a variation, when possible to use a messenger, to send a vessel containing the required amount of the liquid itself might be suggested as an innocent way of communicating a message. But this proposal might not always be entirely practicable.

At the present time, and in this country, for example, consider the plight of the man with a message like this concealed in his hip pocket; or, maybe, with a suit case full of them for delivery to his friends. Almost anything might happen to such a messenger.

Were Æneas alive to-day, he might be able to meet the difficulties that might arise from such a situation, for, as you presently shall see, he was also an adept at concealment. It might be expecting too much to say that he could dispose of a whole suit case full of messages on short notice, but that he was able in the art of hiding them, is revealed in his schemes for conveying intelligence into or from besieged towns.

As one method of accomplishing this, Æneas suggests the application to a sore leg of a manuscript bearing the desired message, instead of a bandage or plaster.

Another of his deceptions consisted of first inscribing the message upon thin sheets of lead, which were then to be rolled into the form of earrings or other ornaments.

Again he mentions the sewing up of an epistle within the sole of the messenger's shoe, or the hiding of it under his armpit.

Æneas also suggests the writing of a message upon a bladder, which was then to be placed in an empty bottle and inflated so as to completely fill it, the bottle and bladder then being filled with oil.

By still another subterfuge the message was scratched upon the wood of the ordinary writing tablet used in those times. This real message was then concealed by covering over the tablet with wax, upon which was written, in the usual way, an apparent message of no importance.

Messages so concealed could have been still further obscured, if desired, by being written in cipher, so that even if the courier were intercepted and the message discovered, it would avail the finder nothing if he were unable to penetrate the cipher.

Compared with some of the ciphers subsequently devised, those of Æneas are relatively simple. However, an account of the few that have been preserved will bear still further evidence of his ingenuity and resourcefulness.

A favorite method of his seems to have consisted in affixing small dots to the letters of a manuscript or epistle on a common subject, the letters so indicated expressing the secret message, and all the rest being nonsignificant. The following example, where the concealed message is SEND AID, might be taken as an illustration of this method:

OUR STRONGHOLD IS BEING
ABLY DEFENDED AND WE
ARE WELL PROVISIONED.

This cipher may be considered the prototype of that class of ciphers where only a part of the characters convey the secret message, the rest having no significance.

A device of this kind was used in the time of Niccolo Machiavelli, Italian statesman of the late fifteenth and early sixteenth centuries, when it appears that a certain person interlined private marks in letters of excommunication that were to be publicly affixed, thus communicating his secret intentions to his confederates.

Incidentally, Machiavelli is the author of a famous treatise expounding those principles of political cunning and artifice intended to promote arbitrary power, since designated Machiavellism. And it is this same Machiavelli that Benito Mussolini, Fascist dictator of present-day Italy, holds up as his tutor and master.

This cipher is also said to have been formerly much used in England by those who wanted to avoid paying the excessive postage rates on letters of a shilling or more for each hundred miles. The sight of a workingman writing to a friend by dotting the letters in the closely printed columns of a parliamentary debate in an old newspaper, which would travel free by the regulations then existing, is said to have been not at all uncommon.

The cipher is, of course, susceptible of many variations. Thus, the significant letters, instead of being marked with ink or pencil, may be indicated by minute scratches, or pin punctures, the puncture cipher being of German origin. Better still, sympathetic inks may be used, when the marks will remain invisible until the paper is heated, or dipped in water, or treated scientifically with the proper chemical reagent.

Further, the method of the cipher, instead of the manner of writing it, may be varied. Thus, Johann Kliiber, in his Kryptographik Lehrbuch, published in 1809, recommends the use of small points, strokes, or little tails under the words, syllables, or letters of a printed or written work, that form a part of the secret message.

The cipher attributed to Sir John Trevanion—see FLYNN'S for January 17, 1925—in which the third letter after each punctuation mark was a significant, is a variation of the Æneas cipher where a specially constructed apparent message is required to carry the real one.

The second cipher in this issue illustrates still another variant of the Æneas dot cipher, described in the Schola Steganographia of Gaspar Schott, published in 1665.

By this method the correspondents prepare an alphabet in which each letter is represented by a different number. Any arrangement of numbers can be used. But in the following alphabet the smallest numbers have been assigned to the most frequently used letters, in accordance with the table in FLYNN'S for January 23, thus reducing cryptograms to the minimum in length.

A  B  C  D  E  F  G  H  I  J  K  L  M
3  20 14 10 1  12 18 8  6  24 22 11 15
N  O  P  Q  R  S  T  U  V  W  X  Y  Z.
5  4  17 25 9  7  2  13 21 16 23 19 26

The letters of the secret communication are replaced by their numbers, which are in turn represented by dots placed at the proper intervals under the letters of any printed article, letter, or other piece of writing of an unsuspicious character, and of suitable length.

In the following illustration the first dot is under the 14th letter, counting from the beginning; the second dot is under the 4th letter following the first dot; and so on. The four dots of the cryptogram in this way stand for the four numbers, 14-4-1-15-1, which in the above alphabet signify C-O-M-E, the secret message.

REMAIN WHERE YOU NOW ARE
UNTIL FURTHER ADVISED.

To decipher such a cryptogram in an unknown alphabet, as No. 2 below, render it into the series of numbers indicated by the dots, which can then be solved by methods commonly applied to simple substitution ciphers.

In another of the ciphers of Æneas, points are used in place of the vowels, thus:

A   E   I   O   U   Y
DOTS 1 DOTS 1BLANKDOTS 1BLANK DOTS 2BLANKDOTS 1BLANK DOTS 2BLANKDOTS 2BLANK DOTS 2BLANKDOTS 2BLANKDOTS 1BLANK DOTS 2BLANKDOTS 2BLANKDOTS 2BLANK

To illustrate this manner of secret writing, Æneas gives the following short examples, signifying: (1) Dionysius Pulcher, and (2) Heraclides Venito, respectively.

(1) D
DOTS 2BLANKDOTS 1 DOTS 2BLANKDOTS 2 N DOTS 2BLANKDOTS 2BLANKDOTS 2 S DOTS 2BLANKDOTS 1 DOTS 2BLANKDOTS 2BLANKDOTS 1 S   P DOTS 2BLANKDOTS 2BLANKDOTS 1 L C H DOTS 1BLANKDOTS 1 R
(2) H DOTS 1BLANKDOTS 1 R DOTS 1 C L DOTS 2BLANKDOTS 1 D DOTS 1BLANKDOTS 1 S    V DOTS 1BLANKDOTS 1 N DOTS 2BLANKDOTS 1 T DOTS 2BLANKDOTS 2 

This cipher employs a partial substitution alphabet; that is, one in which some of the letters are represented by substitutes in cipher, the rest retaining their normal alphabetic values. And it is the predecessor of numerous systems using substitutes for the vowels only, or arrangements of dots to express letters.

Vowel substitution ciphers seem to have been used in Germany as early as the eighth or ninth centuries; in Spain in the eleventh century; and in Italy in the thirteenth century.

In these ciphers the vowels were variously represented by arbitrary signs, other letters, and various arrangements of points or crosses. The following cipher, offering a choice of vowel substitutes, was used in A. D. 1226, and may be cited as a representative example.

A E I O U
X XX XXX XXXX XXXXX
DOTS 1 DOTS 2 DOTS 3 DOTS 2BLANKDOTS 2 DOTS 2BLANKDOTS 1BLANKDOTS 2

One of the forms of Bartolomeus in this cipher would be:

BXrt
DOTS 2BLANKDOTS 2lXXXXmDOTS 2XXXXXs

Another cipher of this general type employing the first five numerals for the vowels, and Greek characters for the consonants, was used for private memoranda by Dr. Rawley, confidant of Sir Francis Bacon.

There are numerous later instances where the use of dots has been extended to the whole alphabet. The Blair dot writing—see FLYNN'S for July 25 and August 15, 1925—is an illustration of this. And the point character for the blind invented by Charles Barbier and arranged by Louis Braille, also the New York point of William B. Wait, may be mentioned as other examples. To those not familiar with alphabets for the blind, such writing is in effect cipher, and is capable of resolution by methods applicable to the latter.

Again to return to Æneas, there is yet to be described another artifice of his, consisting of a board or tablet provided with twenty-four holes representing the twenty-four letters of the Greek alphabet, in any order as agreed by the corresponding parties. A thread or cord was then passed through the holes for the different letters, in the same order as they occurred in a message.

An adaption of this most ingenious device to a twenty-five-letter alphabet, in which the letters I-J are represented by the same hole, is illustrated in cipher No. 1, herewith. The dotted lines show the course of the string passing through on the other side of the tablet.

On account of graphically illustrating a message of any considerable length, the present cipher is necessarily short. But this has been compensated by using a systematic disposition of the alphabet.

By assuming that the holes used more than once signify some of the more frequently used letters, the arrangement of the alphabet, and hence the enciphered message should be readily discovered.

This device is the forerunner of a host of string and diagrammatic ciphers, many of which will be taken up later. In some of these the letters are indicated by marks or knots on the string. In others the letters are graphically represented by points, lines, or geometrical figures used to supplant the string of the Æneas cipher.

From what has here been written it will be seen that such of the ciphers of Æneas as are known are relatively simple in their structure. What the whole of the twenty modes of secret writing actually were, the world may never know.

Perhaps systems very similar to the lost ciphers, or even identical with them, have since been reinvented by others. In this event the world is the loser not so much in not having systems very similar to those of Æneas and his contemporaries, but rather in not knowing exactly what these systems were.

The day may come when some delver into things of the dim and distant past will unearth further information about Æneas and his ciphers.

But until that time we should be happy in the possession of what has been so fortunately saved.

So ends the chapter on Æneas Tacticus, ancient Greek author, counselor of generals, and maker of ciphers.

CIPHER No. 1 (Æneas Tacticus).

Aeneas Tacticus

CIPHER No. 2 (Gaspar Schott).

"Having understood that I could not be
safe any longer where you are, I have chosen
rather a voluntary banishment, to wander
with my liberty abroad, than to lie under the
daily hazard of losing it at home: 'tis in my
opinion the least of the two evils. 'Tis true
I am innocent; but innocence is not always
a buckler; so that I hope you will not con-
demn, even though you cannot approve my
choice, at least, till you have the particulars
of my case, which expect per next."

WIN A YEAR'S SUBSCRIPTION TO FLYNN'S

A number of fans have shown their faith in their ciphers, and their interest in FLYNN'S and in this department, by offering prizes to the successful solvers of their problems. There are no strings attached to such offers.

It is with great pleasure that we present another such opportunity in this issue. This time it is J. R. Midford, of Maine, that we have to thank. Just read Mr. Midford's letter, and then get busy. Here is a challenge backed by the challenger's confidence.

DEAR SIR:

I would like to have you put this cipher before the "gang" to work on.

It will be a good exercise in the working out of a method, rather than the solving of a cipher, that 1 desire to bring out by the host of solvers that follow the Solving Cipher Department.

This cipher has been sent to four or five places, and has never been solved. There is no catch to it. To the first person sending in the correct solution, showing the system of encipherization, I will give a year's subscription to FLYNN'S.

Hope that I may see this in Solving Cipher Secrets.

J. R. MIDWORD.

97 School Street, South Portland, Maine.

CIPHER No. 3 (J. R. Midford).

CCJJTCCEGCBFADHBDCEAAIJEE
ECEFCJCKBBCGGGLEEEBEEEDCE
AABCABCDEJFDCBJELLBABDALB
DCBBAJIGHIDBCJECCHEJOCGBH
HDDCBIIIJCTCCDEBDEECECGGB
AKBAFFCTAEEIJMEADABBTEAJD
CAEEEHCCFFICEDGGDCJJGHEBL
LBAAGAJDEBBCJMAHNFBDAIIEA
FFCCAAMICFCAJADTEKDCGHJJI
ECDBBBBAAGGCCCGACEBHBBANF
FIDDCBAJHBDIIFIFGJOIFTAQB
FIIFEIDBJHGHKBMBBLDAEAALB
JJJEAJDEJTDDEII.

All answers, to be considered, must be mailed within one month from the date of this issue. Postmarks will determine priority of solutions, and any tie between solutions submitted on the same date will be decided in favor of the one having the best explanation of the cipher.

The solution to Mr. Midford's cipher will be printed in an early installment of this department.

In the next cipher, an original contribution by Philo B. Horton, Kalamazoo, Michigan, there is a certain resemblance to the Æneas string cipher. Counterparts of both the string and tablet are present, though the former is not so obvious as the latter.

CIPHER No. 4 (Philo B. Horton).

37   22 71 24   72     4
    27 74 28         10
    31 87 43         34
    49 91 69         79
    54 98           92
    56             95
1   3   7   2 94 6 60
16   12       8   20 66
39   78       35   23 83
            57   36 85
            70   42 96
88   9   11   19 64 21 75
    45   14   32 67 30  
    52   17   41 84 46  
    89   26   47 90 50  
            62 97 61  
13   55   15   5 58 44  
        18   25 68 48  
        29   33 76 65  
        59   40 81 86  
        63   51 82    
    38           53  
    73           77  
    80              
    93              

Now try this one by Leo Goldsmith, Bronx, New York. We might add as a gentle hint that this is a word cipher, where only certain words are significant. Which ones make up the message?

CIPHER No. 5 (Leo Goldsmith).

Do you know how to solve ciphers? You can imagine how simple it would be if all were of this type. Believe it or not, this can be solved very easily if you have the key, but if not it may give you a jolt or two. That is all there is to it. It is easier to solve than to compose it. Is worth trying, anyhow. Always try. Best results come from trying. To try is to succeed. Read it carefully. FLYNN'S magazine leads all others. First, last, and always. I believe in that. Do you?

A. P. Schmutz, of Philadelphia, Pennsylvania, whose name has appeared quite frequently on our lists of solvers, herewith submits a cipher to puzzle those who have been puzzling him.

Mr. Schmutz's cipher, of which he does not claim the invention, is, like No. 4 above, also somdwhat after the style of the Æneas string cipher. Fin d the string here and the worst is over, for the letters of the message are strung upon its network like so many beads.

CIPHER No. 6 (A. P. Schmutz).

F-d, 11; R-M, Q, c, m, z, 15; I-E, I, U, s,
9, 16; D-a, v; A-W, y, 7; Y-h, 8; W-X ; E-L,
O, R, b, n, p, u, w, 3; M-k, 2, 6; U-e, 14; S-A,
N, T, V, r, 17; T-S, 1, 5, 10; G-G, 22; O-B,
Y, j, 13, 20; P-J, l, x; L-C, f, g, 12, 19; H-K,
o, 18; N-F, Z, q, 4, 21; C-H, P, i ; V-D, t.

The key to the following cipher by A. W. Sweeten, Sharon Hill, Pennsylvania, is an original and valuable contribution to cryptography. By its means the letters of a message are transformed into numbers, and by an additional mathematical process these become the numbers of the cipher. Full details of the system will be given in the next article.

CIPHER No. 7 (A. W. Sweeten).

63 45 78 06 10 75 74 22 54 52
02 21 13 06 55 64 66 00 49 47
11 36 75 42 53 42 80 04 68 85
34 67 44 12 12 31 52 04 84 18
78 03 54 58 02 72 61 56 13 06
55 72 53 40 04 68 85 13 06 55
72 53 40 04 61 O5 33 32 46 15
56 40 04 72 73 16 16 67 63 65
88 62 56 21 35 25 68 63 55 84
49 59 60 33 10 22 40 20 89 40 
60 99 12 80 76 38 41 74 71 95
5o 32 85 83 52 25 75 71 22 29
5O 65 40 18 78 03 71 96 63 51
21 51 63 55 84 49 60 99 12 48
30 18 29 85 71 96 63 12 41 78
54 59 25 04 64 95 49 10 68 54
80 21 04 72 75 61 81 53 6s 55
23 04 72 75 38 61 42 15 59 43
62 53 12

The solutions and explanations of all the ciphers in this article, with the exception of No. 3 as above mentioned, will be given in full in next Solving Cipher Secrets. In the meantime sharpen up the old pencil, work out as many solutions as possible, and submit your results with your questions or comments.

SOLVING THE MARCH 20 CIPHERS

The solution of almost any cipher is often simplified when the presence of certain words in the message is known or suspected.

Thus in the instance of the first of the two Nihilist transposition ciphers in the March 20 FLYNN'S, by information given in the article, one of the names—Stone Bridge, Little Garden Street, or Catherine Canal—can be looked for in the cipher.

The message, consisting of two hundred and forty-two letters, could only have been enciphered in two eleven by eleven squares, and tests would indicate that it had been written in straight horizontals.

Having prepared the slips on this basis as per instructions it would only be necessary to try combinations forming parts of the above words to reach the solution.

The keyword used was GRINEWITSKY (2-7-3-6-1-10-4-9-8-5-11), the name of the Czar's assassin given in the message itself, as will be seen in the complete translation:

The Czar returned by way of the Catherine Canal, where a young woman gave the signal by waving a handkerchief. The first bomb damaged the carriage, killing and wounding a number of Cossack guards. The second bomb, thrown by a student named Grinewitsky, killed both the Czar and the assassin himself!

In the case of cipher No. 2, however, no suggestion was given to aid the decipherer, who was thus thrown upon his own resources. This message, also written in straight horizontals, was enciphered in four seven by seven squares by means of the keyword SIBERIA (7-4-2-3-6-5-1). Here is the translation:

We live on black bread in a cold, damp, and suffocating atmosphere, continually threatened with bayonets and the butt ends of muskets, and only kept alive by the single hope of being able to return home once more to see those near and dear to us.

Both of the above messages exactly filled their squares without the use of nulls. In this connection, in solving this kind of cipher, it must be borne in mind that sequences in the last few lines might not form a part of the message.

In cipher No. 3, by T. E. Clayton, Christchurch, New Zealand, each two-letter syllable represented a number of two figures, which in turn was the substitute for a letter in the following alphabetic key:

    1  2  3  4  5  6
1   A  F  K  P  U  Z
2   B  G  L  Q  V
3   C  H  M  R  W
4   D  I  N  S  X
5   E  J  O  T  Y

Both stages of the decipherment are subjoined:

NI  DO  JE  LE  LI       MI  HE  TE  LI  TA
44  53  23  25  42       43  22  31  42  14
 S   O   L   V   I        N   G   C   I   P

VE  BO  BI  NI  BO       TE  BI  BO  FO  NI
32  51  34  44  51       31  34  51  54  44
 H   E   R   S   E        C   R   E   T   S

By this method a given syllable always represents the same letter. Hence the cipher can be solved by simple substitution methods without knowing anything about the system.

Further, a study of the values of the few syllables in the cipher should make it possible to reconstruct the whole of Mr. Clayton's key. Try this as a method of solving the following three code words, some of the syllables of which are not in the above cipher, and let us know what success you have:

VEBOJEJEDO MIBOCIZABO PAJEPAMIKI

As mentioned in the previous article, cipher No. 4 (James R. Cain) is straight Nihilist, but written to elude the special method for this cipher given in FLYNN'S for June 27, 1925.

This was done by using a keyword, the numerical differences of whose letters were as small as possible—the word being DEEDED (14-15-15-14-15-14) in this case and by wording the message so that no number would occur in the cipher smaller than the largest key number plus 11, or larger than the smallest key number plus 55—the numbers actually running from 26 to 69 inclusive in the example submitted.

The result of this method is that no difference larger than 4 can occur between the units or tens figures of any two numbers. This evades the method above mentioned. But it can still be handled by that given in FLYNN'S for October 10, 1925, and by other methods yet to be treated in future issues.

Mr. Cain's message was: " True cipher bugs do not admit defeat, but try until they succeed. Simple codes cause more blunders than complicated ones."

This small portion deciphered will show how the wording has been modified to suit the conditions:

 T  R  U  E  C  I  P  H
44 42 45 15 13 24 35 23
14 13 15 14 15 14 14 15
—— —— —— —— —— —— —— ——
58—57—60—29—28—58—49—38—
 E  R  B  U  G  S——etc.
15 42 12 45 22 43——etc.
15 14 15 14 14 15——etc.
—— —— —— —— —— ——
30—56—27—59—36—58——etc.

Observe that BUGS (27-59-36-58) has been used instead of FANS (36-25-47-58), in order to avoid the telltale 25. Mr. Cain's method, though ineffective, is nevertheless ingenious.

No doubt many fans are curious to know what slogan Frank Spalding, of Wrangell, Alaska, concealed in cipher No. 5. Also a few readers might complain of the shortness of his cipher. It must be remembered, however, that it is cold away up there in Alaska, and that Mr. Spalding probably had to work fast to keep from freezing.

As it was he finished it in half the time by using the first half of the slogan as the key for the second half:

N  U  T  S  N  U  T  S
33 45 44 43 33 45 44 43
W  E  H  A  V  E  E  M
52 15 23 11 51 15 15 32
—— —— —— —— —— —— —— —— 
85—60—67—54—84—60—59—75

The slogan: "NUTS! NUTS! WE HAVE 'EM! "

Cipher No. 6 (J. Levine) used the longest key of any Nihilist cipher submitted, because the key was as long as the message, both of which, incidentally, are quotations from the June 27, 1925, cipher article.

The key: " As a general rule, as the length of the message decreases, or that of the key increases t— "

The message: "The climax is reached when the key is as long as, or even longer than, the message itself."

In solving a cipher with a continuous nonrepeating key, such as this, it is a good idea to look for a common word, as THE, the substitutes for which must be within the limits of from 11 to 55 larger than 44-23-15.

Of twelve possible sequences -66-67-38- seems to offer the most favorable hold:

—66—67—38—
  T  H  E
 44 23 15
 —— —— ——
 22 44 23
  G  T  H

For GTH might be the ending of a word like lenGTH, strenGTH, etc., or possibly the ending of one word and the beginning of another, as havinG THe, etc. By trial, LENGTH as a key gives HENTHE in the message, suggesting WHEN THE, tHEN THE, etc.

In this way both sentences can be developed at the same time, working both forward and backward in the message. Of course, almost any other point, or any other word might start the solution.

In cipher No. 7 (Benjamin Miller-Samuel M. Kurtz ) an original and most unusual method of encipherment was employed. Each letter of the message was first replaced by the two figures from the alphabetic key. These figures were then regrouped by threes, and for each group was substituted the six figures of its natural or Naperian logarithm from a five-place table, thus:

Message:     P    R    O     B    A    B     etc.
Substitute:  35   42   34    12   11   12    etc.
Regrouped:   354      234    121      112    etc.
Logarithm:   126413   085015 019062   011333 etc.

The whole message is: "Probably the simplest form of cipher is the simple substitution cipher in which some other character is used to replace each letter of a message."

Mr. Miller, in an interesting paper on the cipher, which it is to he regretted cannot he printed in full, mentions that the cipher can he varied almost indefinitely by using logarithms to other bases or to different numbers of places, or by regrouping by twos, fours, fives, etc., instead of by threes, thus providing a different variant for each day of a cryptographer's lifetime.

The use of logarithms might appear tedious and slow. But actually they are not nearly so cumbersome to use as would at first thought he imagined. Perhaps a more serious objection to logarithms, when they appear in the cryptogram, is that they are recognizable as such, serving in themselves to identify the table from which they were taken.

Also it must he mentioned that the use of logarithms in cryptography is not exactly new. One instance of such a cipher is the so-called holocryptic cipher devised some seventy years ago by Pliny Earle Chase, a mathematician. This cipher may later he described in these columns.

WITH THE FANS

The list of solvers of the January 23 ciphers is not as lengthy as might he. Somehow these ciphers must have stumped the fans.

No. 3, the ten-dollar prize cipher by Hohart Hollis, failed to get a rise from the audience. And likewise answers to No. 2, a sight reading cipher to any one in the secret, and No. 5, by Mrs. E. J. Hyatt, were conspicuously absent.

Mr. Winsor, who was successful with No. 1, the Tyler-to-Poe cipher, submits the following query:

I see that Mr. Bellamy succeeded in solving No. 4 of October 31. My hat is off to him on that. Might it be of interest to print his method of attack?

Mr. Bellamy had this to say about the solution of the cipher in question:

No. 4 was easy, as W would not be E or a space, so is a number or digit. Arranged by frequencies, the word WASHINGTON stands out as a key; not a good word as N=either 6 or 0, making WN—either J or P, and AN=either T or Z. Still a good one to sharpen one's wits on.

Mr. Weinert also submits a question:

This is the first time I have seen FLYNN'S, and also the first cipher I have ever succeeded in solving. The others in this issue are 'way over my head. Can you recommend a book on ciphers?

A canvass of publishers reveals the startling fact that there is not a single work on cryptography in print in the English language. Any new books on the subject, or new editions of older works, will be announced here when published.

Solutions to the February 20 Vigenère ciphers are, at this writing, arriving in numbers and in kind that portend a generous and interesting list of solvers for publication in the next issue of this department in FLYNN'S for May 22.