CRYPTOGRAPHY.
The meaning of the word “Cryptography” is, as is well known, “hidden or secret writings,” and was used in ancient times, when conspiracies were common, and murders an every-day occurrence, as the means of communicating from one person to another in such a manner that it could not be read by any one save those who were admitted into the secret of its construction.
A widespread conspiracy, or, as it would be more properly termed, rebellion, could not be carried on between persons at a distance from each other unless they resorted to cryptography; in fact, the means of correspondence was in those times of so slow and dangerous a nature, that without the utmost care and secrecy in the arrangement of the cipher it would certainly have been discovered, and then death would be the consequence.
In order to mature their designs in safety, and to throw off all suspicion, men were obliged to put their wits to work and invent some way of informing each other of everything that did transpire, so that no one else should be the wiser for it: thus was cryptography discovered; and wonderful cunning and ingenuity were displayed in its construction, as will be seen by the examples that are given.
It was also used in former times in transacting affairs of state, in communicating messages from one general to another in time of war, and in many other ways of a more innocent nature, too numerous to mention.
Now, at the present time, when all is peace and prosperity, and news is brought to our very doors by post and telegraph, cryptography is only interesting as a curious study, or to amuse ourselves in an idle hour by finding out its hidden mysteries.
The first and most common form of cryptograph we read of was by the transposition of letters, and is, as we may see, capable of great improvement; indeed, it is the basis on which most of the letter ciphers are formed at the present day.
We give the following as an example:—
| For— | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z. |
| Use— | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z | a | b | c. |
The sentence, “We meet to-night,” in this cipher would become, “Zh phhw wr-qljkw.”
The next is formed on the principle of the above, but is rather more intricate: for instance, if we wanted to inform some one that, “All going on well, send supplies as soon as possible,” we should put it down in the following order:—
| a | g | s | p | s | o |
| l | o | e | l | o | s |
| l | n | n | i | o | s |
| g | w | d | e | n | i |
| o | e | s | s | a | b |
| i | l | u | a | s | l |
| n | l | p | s | p | e |
You must read it down the first perpendicular column, then down the second, and so on. You must then form the letters in the horizontal columns into imaginary words, and place them down on paper as you would a common sentence, thus:—“Ag spso loelos lnn iosgwden ioes sab iluas lnlp spe.”
You must arrange with your correspondent beforehand that the width of the horizontal column should consist of six letters (or more, if you like); so by placing the letters six in a line, one under the other, without regard to words, the puzzle is easy to solve.
Another good cipher is by using the figures 1 and 2 differently arranged for every letter in the alphabet, as will be seen by the following key:—
| a | b | c | d | e | f | g | h | i |
| 11111 | 11112 | 11121 | 11122 | 11211 | 11212 | 11221 | 11222 | 12111 |
| j | k | l | m | n | o | p | q | r |
| 12112 | 12122 | 12211 | 12212 | 12221 | 12222 | 21111 | 21112 | 21121 |
| s | t | u | v | w | x | y | z | |
| 21122 | 21211 | 21212 | 21221 | 22222 | 22212 | 22221 | 22122 |
Now if we wanted to write the words “Come now,” we should do it in this way, knowing that there are five figures to every letter, and when a word is formed there is a comma:—
11121122221221211211, 122211222222222.
The next was a favourite of that unfortunate king, Charles I.:—
| a | b | c | d | e | f | g | h | i & j | k |
 |  |  |  |  |  |  |  |  |  |
| l | m | n | o | p | q | r | s | t | u & v |
 |  |  |  |  |  |  |  |  |  |
| w | x | y | z | ||||||
 |  |  |  | ||||||
The next is rather good and somewhat difficult:—
Divide a piece of cardboard into twenty-six departments, and in each place a letter; then take another piece (small enough that the letters on the first piece can be seen), and fit it into the centre of the first, dividing this into the same number of departments; then put a piece of thread through the centre of both, so that you can turn the smallest card round, filling the spaces up with letters in any way you like. Thus:
In using the dial, turn it round until, say, the letter m in the middle card comes under the letter A in the outer circle; next take what you want to write, and find it letter by letter in the outer circle, putting down on paper what appears directly under it in the inner circle.
Now if you want to write “I shall come soon,” first write the letters A m, so as to enable your correspondent to fix his dial like your own, as the A is in the outer circle and the m under it in the inner—“Am d ufmyy rjxi ujjk.”
You may arrange your dial in any way you like, but must be sure to place what letter is under the A at the beginning of your cipher.
The next is something like the last:—
Now if you want to tell some one that “They are all coming over,” you must write it down and place the figures 5, 4, 3 over every letter in succession. Thus:—
| 5 | 4 | 3 | 5 | 4 | 3 | 5 | 4 | 3 | 5 | 4 | 3 | 5 | 4 | 3 | 5 | 4 | 3 | 5 | 4. | ||||
| T | h | e | y | a | r | e | a | l | l | c | o | m | i | n | g | o | v | e | r. |
Then look for the letter T in the dial; the figure 5 being over it, you must look for the fifth letter from it, which is O: put it down, and go on to the next letter in the message, H; find H in the circle, and as 4 is over it, put down the fourth letter from it, D: for E, with the 3 over it, we must write down the third letter from E; and for the next letter, Y, 5 being over it, the fifth letter; and so on, always counting in the direction of the arrows. The cipher will run eventually: “Odbt woz wig ylhekb kszn.”
The way to read this cipher is to put 543 down the same as before, and to count them on the circle in the opposite way to which the arrows are pointing.
The most famous and complex cipher perhaps ever written was by Lord Bacon. It was arranged in the following manner:—
| aaaaa | stands for | a |
| aaaab | „ | b |
| aaaba | „ | c |
| aaabb | „ | d |
| aabaa | „ | e |
| aabab | „ | f |
| aabba | „ | g |
| aabbb | „ | h |
| abaaa | „ | i & j |
| abaab | „ | k |
| ababa | „ | l |
| ababb | „ | m |
| abbaa | „ | n |
| abbab | „ | o |
| abbba | „ | p |
| abbbb | „ | q |
| baaaa | „ | r |
| baaab | „ | s |
| baaba | „ | t |
| baabb | „ | u & v |
| babaa | „ | w |
| babab | „ | x |
| babba | „ | y |
| babbb | „ | z |
Now, suppose you want to inform some one that “All is well;” first place down the letters separately according to the above alphabet—
aaaaa ababa ababa abaaa baaab babaa aabaa ababa ababa.
Then take a sentence five times the length in letters of “All is well,”—say it is, “We were sorry to have heard that you have been so unwell.”
Then fit this sentence to the cipher shown above, like this—
| a | a | a | a | a | a | b | a | b | a | a | b | a | b | a | a | b | a | a | a | b | a | a | a | b | b | a | b | a |
| W | e | w | e | r | e | s | o | r | r | y | t | o | h | a | v | e | h | e | a | r | d | t | h | a | t | y | o | u |
| a | a | a | b | a | a | a | b | a | b | a | a | b | a | b | a. | |||||||||||||
| h | a | v | e | b | e | e | n | s | o | u | n | w | e | l | l. | |||||||||||||
Marking with a dash every letter that comes under a B. Then put the sentence down on your paper, printing all marked letters in italics, and the others in the ordinary way, thus—
“We were sorry to have heard that you have been so unwell.”
The person who receives the cipher puts it down and writes an A under every letter except those in italics; these he puts a B under; he then divides the cipher obtained into periods of five letters, looks at his alphabet, and finds the meaning to be, “All is well.”
Here is a specimen of a music cryptograph:—
The next is good, but rather lengthy:—
| a | b | c | d | e | f | g | h |
| . : . . . | : . . . : | . : : . . | . . . : . | . . . . : | . : . : : | . . : . . | : . . . . |
| i | j | k | l | m | n | o | p |
| : : . . . | . . : : . | . : . : . | : . : . . | . . . : : | . . : . : | : : : . . | . : : : . |
| q | r | s | t | u | v | w | x |
| : : : : : | : : . : : | : . : . : | : : . . : | : . : : . | : : : : . | . : : : : | : : : . : |
| y | z | ||||||
| : . : : : | . : : . : | ||||||
Here is the key of another:—
| 1 | 2 | 3 | 4 | 5 |
| a | b | e | d | e—1 |
| f | g | h | i | k—2 |
| l | m | n | o | p—3 |
| q | r | s | t | u—4 |
| v | w | x | y | z—5 |
In picking out the letter you want, you must see under what number it stands, then see what number is at the end of the line, then put those two figures together, and they will represent the letter: thus, 15 represents V; 23, M; 43, O; and 55, Z.
The sentence, “We meet to-night,” would be—2551, 23515144, 4443, 3342223244.
The next is a very difficult and complex cryptograph to decipher.
Draw a table of four columns, like the figure below. In the first column place the six different arrangements of the figures 1, 2, 3, and number the other columns 1st, 2d, and 3d respectively:—
| 1st. | 2d. | 3d. | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 123 | t | y | c | n | h | r | e | m | e | a | o | i |
| 132 | b | e | f | s | y | h | i | s | g | t | r | t |
| 213 | e | r | e | e | t | m | x | w | a | e | n | t |
| 231 | e | r | m | c | k | m | a | r | a | h | h | y |
| 321 | l | m | r | t | i | c | i | h | l | o | e | g |
You must agree with your correspondent how many letters wide each of the three columns shall be—we will say four. Then take your sentence—say it is, “They are coming by the first steamer next week from America; we hope they will come right.” You must then place every letter down separately, writing the figures in the first column in succession over them, thus—
| 1 | 2 | 3 | 1 | 3 | 2 | 2 | 1 | 3 | 2 | 3 | 1 | 3 | 1 | 2 | 3 | 2 | 1 | 1 | 2 | 3 | 1 | 3 | 2 | 2 | 1 | 3 | 2 | ||
| T | h | e | y | a | r | e | c | o | m | i | n | g | b | y | t | h | e | f | i | r | s | t | s | t | e | a | m | ||
| 3 | 1 | 3 | 1 | 2 | 3 | 2 | 1 | 1 | 2 | 3 | 1 | 3 | 2 | 2 | 1 | 3 | 2 | 3 | 1 | 3 | 1 | 2 | 3 | 2 | 1 | 1 | 2 | 3 | 1 |
| e | r | n | e | x | t | w | e | e | k | f | r | o | m | A | m | e | r | i | c | a | w | e | h | o | p | e | t | h | e |
| 3 | 2 | 2 | 1 | 3 | 2 | 3 | 1 | 3 | 1 | 2 | 3 | 2 | 1. | ||||||||||||||||
| y | w | i | l | l | c | o | m | e | r | i | g | h | t. | ||||||||||||||||
Over the first letter, “t,” stands “1,” therefore write “t” in the column marked first; over “h” is “2,” therefore write “h” in the second column; over “e” is “3,” then put “e” in the third column, and so on; but when four letters are written abreast you must begin a new line.
After doing the above, you must take the letters in each column separately (beginning with the first), and form them into imaginary words, putting a dot under the last letter of each column to show your correspondent that the column ends there; thus—
Tycnb efse ree ermc w pee lmrt hrem yhistmx wk mar eot wi ciheaoi gtrtae ntfoei ah hyl oegg.
Tycnb efse ree ermc w pee lmr• hrem yhistmx wk mar eot wi ci•eaoi gtrtae ntfoei ah hyl oeg•
The person receiving the message knows the width of the column (four letters), the arrangement of the figures 1, 2, 3, and the use of the dots, and reconstructs his table directly; he then puts the letters in order by a backward process to the one we have gone through, and reads the message.
The next is a cipher of a different kind:—
The dots stand for the last letter in each square: thus O would be , and P the same with a dot put in the middle, thus • . A and B •
The sentence, “Routledge’s Magazine for Boys,” would be
In finding out the meaning of a cryptograph, you must first settle in your mind to what class of cipher it belongs, whether it is written by means of letters, figures, or signs; having done so, you must go to work with patience, and try to find out, by means of perseverance and study, what each figure, sign, or letter represents; as even the above specimens of cryptography can be so altered and improved upon, yet continuing in their original form to some extent, that it would be impossible to give positive rules to enable any one to decipher any kind of cryptograph; in fact, it can only be done by those who have made it their study for years, and consequently have had great experience in the matter.
Most of the examples given will only enable one to decipher the most simple kinds, such as are generally found in magazines, &c.; for if that intricate cipher of Lord Bacon’s were put in a book for boys, it would be a waste of paper, as we will venture to say that not one in a thousand would be able to find it out.
There is another class of cryptographs which we have not yet noticed, and which are done by means of sympathetic inks, a list of which will consequently be interesting.
Inks which appear when heated, and become invisible when cooled:—
Solution of nitro-muriate of cobalt; when heated turns green.
Solution of acetate of cobalt, with a little nitre; rose-colour when warm.
Inks which remain visible when heated, but do not disappear when cooled:—
Onion-juice, yellow; equal parts of copper and sal-ammoniac in water, yellow; aquafortis, spirits of salt, oil of vitriol, and salt and water, yellow or brown.
Inks which appear when exposed to light:—
Diluted solution of nitrate of silver.
Diluted solution of terchloride of gold.
PETER POUNCE, THE FIRST TEACHER OF THE DEAF AND DUMB, INSTRUCTING A BOY.