what is Computer encryption

Computer encryption is based on the science of cryptography, which has been used as long as humans have wanted to keep information secret. The earliest forms of encryption where the scytale’s and the creation of cipher texts. These forms of cryptography would rely on both parties knowing the key used or the correct cipher before the message could be delivered. Here's an example of a typical cipher, with a grid of letters and their corresponding numbers:

1 2 3 4 5
1 A B C D E
2 F G H I/J K
3 L M N O P
4 Q R S T U
5 V W X Y Z

If a general wanted to send the message “I love ponies” he would write the series of corresponding numbers: 42 13 43 15 51 53 43 33 42 51 34. Only the person with this cipher text would be able to reach the message. Now obviously, to make the message more difficult to decipher, the letters inside the table would be arranged differently. Computer encryption uses algorithms to alter plain text information into a form that is unreadable. Most people believe that AES will be a sufficient encryption standard for a long time coming: A 128‐bit key, for instance, can have more than 300,000,000,000,000,000,000,000,000,000,000,000 key combinations. Today’s AES standard is AES 256bit encryption which has 256 ^ 2 possible combinations.

As we said before, there are many reasons for encryption. One purpose of encryption is the act of transforming data from a state that is readable to a state that cannot be read by a third party that does not have permission. The result of the process is encrypted information (in cryptography, referred to as ciphertext).

The reverse process, i.e., to make the encrypted information readable again, is referred to

as decryption (i.e., to make it unencrypted). It is also important to know that the word  ncryption can implicitly refer to the decryption process. For example, if you get an encryption program, it encrypts information as well as decrypts it.

There are two types of encryption that should be used for two different purposes: symmetric (private key encryption) and asymmetric (public key encryption). Symmetric encryption is used the most because it is fast, easy to use, and is the most widely needed. You will use this form of encryption when there is only one password being used (such as TrueCrypt or another simple file encryption utility).

Asymmetric encryption on the other hand uses two keys, one to encrypt information and the other to decrypt the information.