Cryptography

Cryptography is way you can keep information

secure. A person who does not know the

method used to change the information to

keep it secure cannot copy the method used or reverse the change. The basic

components of cryptographic systems are used to en cipher (scramble) information

so that it is difficult to determine the meaning without the appropriate

key or key(s) to decipher (unscramble) the information. The components

include cryptographic algorithms (mathematical functions) for enciphering

or deciphering information and keys.

Symmetric and asymmetric are two examples

of cryptographic systems. Symmetric systems use the same key to encipher

and decipher. Asymmetric systems

generate and use different keys to encipher

and decipher a secure key pair. With this key pair, consisting of a public

key and a private key, only one key can decipher what the other enciphers.

Merely knowing one key does not make it

very likely that someone will be able to figure out the other key. Asymmetric

key pairs are used in creating digital signatures and transporting symmetric

keys.

In the past, most encryption systems only

used symmetric cryptography. The problem with symmetric cryptography though,

is the difficulty encountered in distributing keys to certain people. Since

symmetric cryptography uses the same key for enciphering and deciphering,

a person has to use creative and difficult means to prevent someone from

intercepting the key. If a third party were to intercept the key, they

could use it to decipher anything it was used to encipher.

A solution to this problem is public key

cryptography which uses asymmetric cryptography to transport symmetric

keys. In such a system, a recipient\'s public key is used to encipher a

symmetric key. Once enciphered, the symmetric key can only be easily deciphered

using the corresponding private key.

Keys can be of varying length, typically

from 128-bits to over 2000-bits. Obviously, the larger the key, the more

secure the information you’re encrypting.