In encryption, a message is referred to as plaintext before changing it in any way. Data encryption is the process whereby plaintext data is converted to ciphertext data. Ciphertext data can only be read by a party with a secret decryption key. A method for encrypting text is referred to as a cryptosystem. There are many uses for encryption today, particularly, with the widespread use of the Internet.
Encryption is used to verify messages, validate and authenticate users and authorize transactions.
Banks use encryption to secure customer identification numbers at ATM machines. All U.S. electronic funds transfer messages are encrypted. Online vendors depend upon the security of credit card transactions in conducting business. Many political groups use cryptography to protect the identity of online users. Anonymity is vital to both privacy and freedom of speech.