Cryptographic communication and authentication
Paul Krzyzanowski · 2004
We will refer to a message that is readable, or not encrypted, as plaintext, cleartext and denote it with the symbol M. The process of disguising a message to hide its substance is called encryption. We will represent this operation as E(M). The encrypted message, C=E(M) is called ciphertext. The process of turning ciphertext back into plaintext, M=D(C), is called decryption. Cryptography is the art and science of keeping messages secure. In addition to providing confidentiality, cryptography is also used for: