In classical cryptography, the running key cipher is a type of polyalphabetic substitution cipher in which a text, typically from a book, is used to provide a very long keystream. Usually, the book to be used would be agreed ahead of time, while the passage to use would be chosen randomly for each message and secretly indicated somewhere in the message.
Read more about Running Key Cipher: Example, Variants, Security, Confusion
Famous quotes containing the words running, key and/or cipher:
“This place is the longest running farce in the West End.”
—Cyril Smith (b. 1928)
“You have many choices. You can choose forgiveness over revenge, joy over despair. You can choose action over apathy.... You hold the key to how well you make the emotional adjustment to your divorce and consequently how well your children will adapt.”
—Stephanie Marston (20th century)
“It is not an arbitrary “decree of God,” but in the nature of man, that a veil shuts down on the facts of to-morrow; for the soul will not have us read any other cipher than that of cause and effect. By this veil, which curtains events, it instructs the children of men to live in to-day.”
—Ralph Waldo Emerson (1803–1882)