Encryption

Encryption is the conversion of data into a form, called cipher text, that cannot be easily understood by unauthorized people .

Encryption starts with Plain Text. Plain Text is the original, unencrypted message. The Plain Text message is in the clear and can be read by anyone. A cryptographic algorithm is then applied to the Plain Text, producing cipher text. Cipher text is basically a scrambled version of Plain Text that is unintelligible. The algorithm is the method used to encrypt the message. The key is data used to encrypt and decrypt the information. A password or passphrase is commonly used as the key .

Sources:

John Sammons The Basics of Digital Forensics: The Primer for Getting Started in Digital Forensics, Second Edition. Syngress is an imprint of Elsevier. - 85