Symmetric Key Example
Let be the plaintext message that Alice wants to secretly transmit to Bob and let be the encryption cipher, where is a secret key. Alice must first transform the plaintext into ciphertext, in order to securely send the message to Bob.
Both Alice and Bob must know the choice of key, or else the ciphertext is useless. Once the message is encrypted as ciphertext, Alice can safely transmit it to Bob (assuming no one else knows the key). In order to read Alice's message, Bob must decrypt the ciphertext using which is known as the decryption cipher, .
Read more about this topic: Ciphertext
Famous quotes containing the word key:
“The hypothesis I wish to advance is that ... the language of morality is in ... grave disorder.... What we possess, if this is true, are the fragments of a conceptual scheme, parts of which now lack those contexts from which their significance derived. We possess indeed simulacra of morality, we continue to use many of the key expressions. But we have—very largely if not entirely—lost our comprehension, both theoretical and practical, of morality.”
—Alasdair Chalmers MacIntyre (b. 1929)