CIPHER

CIPHER, denotes likewise certain secret characters
disguised and varied, used in writing letters that con-
tain some secret, not to be understood but by those
between whom the cipher is agreed on.

De la Guilletiere, in his Lacedæmon ancient and mo-
dern, endeavours to make the ancient Spartans the in-
ventors of the art of writing in cipher. Their scytala,
according to him, was the first sketch of this mysteri-
ous art: these scytalæ were two rollers of wood, of
equal length and thickness; one of them kept by the
ephori; the other by the general of the army sent on
any expedition against the enemy. Whenever those
magistrates would send any secret orders to the general,
they took a slip of parchment, and rolled it very
justly about the scytalæ which they had reserved; and
in this state wrote their intentions, which appeared
perfect and consistent while the parchment continued
on the roller: when taken off, the writing was
maimed, and without connection; but was easily re-
trieved by the general, upon his applying it to his
scytalæ.

Polybius says, that Æneas Tactitus, 2000 years ago
collected together 20 different manners of writing so
as not to be understood by any but those in the se-
cret; part whereof were invented by himself, and
part used before his time.—Trithemius, Cap. Porta,
Vigenere, and P. Nicéron, have wrote expressly on
the subject of ciphers.

As the writing in cipher is become an art; so is the
reading, or unravelling thereof, called deciphering.—
The rules of deciphering are different in different lan-
guages. By observing the following, you will soon
make out any common cipher wrote in English.

1. Observe the letters or characters that most fre-
quently occur; and set them down for the six vowels,
including y; and of these the most frequent will gene-
rally be e, and the least frequent u.

2. The vowels that most frequently come together
are ea and ou.

3. The consonant most common at the ends of
words is s, and the next frequent r and t.

4. When two similar characters come together,
they are most likely to be the consonants f, l, or s, or
the vowels e or o.

5. The letter that precedes or follows two similar
characters is either a vowel, or l, m, n, or r.

6. In deciphering, begin with the words that con-
sist of a single letter, which will be either a, I, o,
or e.

7. Then take the words of two letters, one of
which will be a vowel. Of these words the most
frequent are, an, to, be, by, of, on, or, no, so, as, at,
if, in, is, it, he, me, my, us, we, am.

8. In words of three letters there are most com-
monly two consonants. Of these words the most fre-
quent are, the, and, not, but, yet, for, tho', how, why,
all, you, she, his, her, our, who, may, can, did, was,
are, has, had, let, one, two, six, ten, &c.*

Cipher. 9. The most common words of four letters are, this, that, then, thus, with, when, from, here, some, most, none, they, them, whom, mine, your, self, must, will, have, been, were, four, five, nine, &c.

10. The most usual words of five letters are, there, these, those, which, were, while, since, their, shall, might, could, would, ought, three, seven, eight, &c.

11. Words of two or more syllables frequently begin with double consonants, or with a preposition; that is, a vowel joined with one or more consonants. The most common double consonants are bl, br, dr, fl, fr, gl, gr, ph, pl, pr, sh, sp, st, th, tr, wh, wr, &c. and the most common prepositions are com, con, de, dis, ex, im, in, int, mis, par, pre, pro, re, sub, sup, un, &c.

12. The double consonants most frequent at the end of long words are, ck, ld, lf, mn, nd, ng, rl, rm, rn, rp, rt, sn, st, xt, &c. and the most common terminations are ed, en, er, es, et, ing, ly, son, sion, tion, able, ence, ent, ment, full, less, ness, &c.

On Plate LXXIX. fig. 7. is given an example of a cipher wrote in arbitrary characters as is commonly practised. It will be easily deciphered by observing the rules: but when the characters are all placed close together, as in the example fig. 8. and as they always should be, the deciphering is much more difficult.

To decipher a writing of this sort you must first look for those characters that most frequently occur, and set them down for vowels as before. Then observe the similar characters that come together; but you must remember that two such characters may here belong to two words. You are next to remember the combinations of two or three characters that are most frequent; which will be some of the words in the seventh and eighth of the foregoing rules; and by observing the other rules, you will infallibly discover, with time and attention, any cipher wrote on these principles.

When the words are wrote all close together, if the key to the cipher were to be changed every word, according to a regular method agreed on between the parties, as might be done by either of the methods mentioned in N^o II. below, with very little additional trouble, the writing would then be extremely difficult to decipher. The longer any letter wrote in cipher is, the more easy it is to decipher, as then the repetitions of the characters and combinations are the more frequent.

The following are the contents of the two foregoing ciphers; in which we have inverted the order of the words and letters, that they who are desirous of trying their talent at deciphering, may not, inadvertently, read the explanation before the cipher.

enil eno ton dna shtnom elohw eerht, suoidifrep dna leure o. noituac & ecnedurp fo klat liw uoy : on, rotiart, teelgen & ecneressidni si ti. yltrohs rettell a em dnes ot snaem emof dnif rehtie, traeh eht morf semoc ti taht ees em tel &, erom ecaf ym ees ot erad reven ro.

evlewt fo ruoh eht ta thgin siht, ledatic eht fo etag eht erofeb elbmesla liw sdneirf ruo lla. ruoh eht ot lautenup eb : deraperp llew emoc dna, ytrebil ruoy niager ot, ylevarb eid ro. thgin eht si siht, su sekam rehtie taht, etiuq su seodnu ro.