To Edgar A. Poe, Esq.
The difficulty attending the cipher by key-phrase, viz: that the same characters may convey various meanings—is a difficulty upon which we commented in our first article upon this topic, and more lately at greater length in a private letter to our friend F. W. Thomas. The key-phrase cryptograph is, in fact, altogether inadmissible. The labor requisite for its elucidation, even with the key, would, alone, render it so. Lord Bacon very properly defines three essentials in secret correspondence. It is required, first, that the cipher be such as to elude suspicion of being a cipher; secondly, that its alphabet be so simple of formation as to demand but little time in the construction of an epistle; thirdly, that it shall be absolutely insoluble without the key—we may add, fourthly, that, with the key, it be promptly and certainly decipherable.
Admitting, now, that the ingenious cryptograph proposed by our correspondent be absolutely what he supposes it, impenetrable, it would still, we think, be inadmissible on the first point above stated, and more so on the second. But of its impenetrability we are by no means sure, notwithstanding what, at a cursory glance, appears to be the demonstration of the writer. In the key-phrase cipher an arbitrary character is sometimes made to represent five, six, seven, or even more letters. Our correspondent proposes merely to reverse the operation:—and this simple statement of the case will do more towards convincing him of his error than an elaborate argument, for which we would neither have time, nor our readers patience. In a key-phrase cryptograph, equally as in his own, each discovery is independent, not necessarily affording any clue to farther discovery. Neither is the idea of our friend, although highly ingenious, philosophical, and unquestionably original with him, (since he so assures us,) original in itself. It is one of the many systems tried by Dr. Wallis and found wanting. Perhaps no good cipher was ever invented which its originator did not conceive insoluble; yet, so far, no impenetrable cryptograph has been discovered. Our correspondent will be the less startled at this, our assertion, when he bears in mind that he who has been termed the “wisest of mankind”—we mean Lord Verulam—was as confident of the absolute insolubility of his own mode as our present cryptographist is of his. What he said upon the subject in his De Augmentis was, at the day of its publication, considered unanswerable. Yet his cipher has been repeatedly unriddled. We may say, in addition, that the nearest approach to perfection in this matter, is the chiffre quarré of the French Academy. This consists of a table somewhat in the form of our ordinary multiplication tables, from which the secret to be conveyed is so written that no letter is ever represented twice by the same character. Out of a thousand individuals nine hundred and ninety-nine would at once pronounce this mode inscrutable. It is yet susceptible, under peculiar circumstances, of prompt and certain solution.
Mr. T. will have still less confidence in his hastily adopted opinions on this topic when we assure him, from personal experience, that what he says in regard to writing backwards and continuously without intervals between the words—is all wrong. So far from “utterly perplexing the decipherer,” it gives him no difficulty, legitimately so called—merely taxing to some extent his patience. We refer him to the files of “Alexander’s Weekly Messenger” for 1839—where he will see that we read numerous ciphers of the class described, even when very ingenious additional difficulties were interposed. We say, in brief, that we should have little trouble in reading the one now proposed.
“Here,” says our friend, referring to another point, “all reasoning would be entirely baffled, as there would evidently be no objects of comparison.” This sentence assures us that he is laboring under much error in his conception of cipher-solutions. Comparison is a vast aid unquestionably; but not an absolute essential in the elucidation of these mysteries.
We need not say, however, that this subject is an excessively wide one. Our friend will forgive us for not entering into details which would lead us—God knows whither. The ratiocination actually passing through the mind in the solution of even a simple cryptograph, if detailed step by step, would fill a large volume. Our time is much occupied; and notwithstanding the limits originally placed to our cartel, we have found ourselves overwhelmed with communications on this subject; and must close it, perforce—deeply interesting as we find it. To this resolution we had arrived last month; but the calm and truly ingenious reasoning of our correspondent has induced us to say these few words more. We print his cipher—with no promise to attempt its solution ourselves—much as we feel inclined to make the promise—and to keep it. Some of our hundred thousand readers will, no doubt, take up the gauntlet thrown down; and our pages shall be open for any communication on the subject, which shall not tax our own abilities or time.
In speaking of our hundred thousand readers (and we can scarcely suppose the number to be less), we are reminded that of this vast number, one and only one has succeeded in solving the cryptograph of Dr. Frailey. The honor of the solution, is however, due to Mr. Richard Bolton, of Pontotoc, Mississippi. His letter did not reach us until three weeks after the completion of our November number, in which we should, otherwise, have acknowledged it.