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—abcdefghijklmnopqrstuvwxyz.
Use—defghijklmnopqrstuvwxyzabc.