A basic explanation of cryptography.

Before I begin, I'll be using these terms a lot:

'Cryptography' is "the field concerned with linguistic and mathematical techniques for securing information, particularly in communications."

'Encryption' is "the process of obscuring information to make it unreadable without special knowledge."

A 'Cypher' or 'Encipherment' is "an algorithm for performing encryption (and the reverse, decryption)  a series of well-defined steps that can be followed as a procedure."
(wikipedia.org)

Cryptography has played a major role in history, and has effected the outcome of many wars. Knowledge is power, which is especially true on the battlefield. If you know your enemy's plans, you can win a war with an army half the size.




So it seems pretty important not to let the enemy find out about your plans. The easiest and safest way would be not to tell anyone, but then, how are the soldiers going to know what to do?
But if you tell anybody, the enemy could intercept the message and use it against you! But what if the enemy didn't understand the message? This is where Cryptography comes in. It is the art of making the message un-understandable to everyone exept those who know how it's encrypted.

There are two main types of cryptography: 'transposition' and 'substitution' encryptions.

In a transposition cypher, the order of letters, words, numbers, or phrases are re-arranged systematically.

In a subsitution cypher, letters, words, or phrases are replaced by other letters, words, numbers, or phrases.

More and more types of encryptions are being invented, especialy electronically. However, most of these are based on the two main types somehow.

As computers and the internet play a bigger and bigger role in our lives, and more and more people try to decrypt passwords and such, more and more encryption methods are needed.

Like all encryptions, even the most secure will eventually become outdated. As the brain of the decryptors evolve, so do the brains of the encryptors...