e secret decoder ring is a classic example of a simple code. Each letter of the alphabet is replaced by an offset. In this scenario A would be C and B is replaced by D, and so on. This allows for the sending of an unreadable message that can be decoded by the person that knows the proper offset. When a line of text is in normal readable form it is considered to be plaintext. Once plaintext is encrypted it becomes ciphertext. The ciphertext produced by present encryption standards follows the same idea as the decoder ring but the algorithms involved are much more complex. Now in today’s world a simple cipher couldn’t protect sensitive data with any measure of real security. There have come about several different approaches to how data is encrypted. They generally fall into two categories normal encryption and public-key encryption. In a standard encryption scheme the message is encrypted with a certain key word that the receiver of the message needs to know to decrypt the message. In public-key encryption the key used to encrypt the message is different from the key used to decrypt the message. This scenario allows one of the keys to become public. In this way the sender can encrypt a message to his friend, using the friends public-key, and there would be no need for any other contact between them for the friend to read the message. This was a problem with standard encryption because the channel used to send the key to the recipient would have to be secure otherwise there would be no reason to use encryption. Another advantage of the Data Encryption Standard was that it was tested to be secure. The testing of the algorithm was accomplished by trying to break the code with a great amount of resources. This type of encryption is a one key form of encryption, which means the channel for the key has to be secure and that the same key is used for decryption. More applications are moving towards the use of RSA encryption. RSA was ...
