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:
“Andrews: Do you mind if I ask a question frankly? Do you love my daughter?
Peter: Any guy that’d fall in love with your daughter ought to have his head examined.
Andrews: Now that’s an evasion.
Peter: She grabbed herself a perfect running mate. King Westley! The pill of the century. What she needs is a guy that’d take a sock at her once a day, whether it’s coming to her or not.”
—Robert Riskin (1897–1955)
“I cannot tell what I am as much afraid of, as a woman who invariably washes on Monday. It is a kind of key to character; and if her mouth is not puckered and her brow wrinkled, they will be, unless she repents.”
—Jane Grey Swisshelm (1815–1884)
“The eye is the first circle; the horizon which it forms is the second; and throughout nature this primary figure is repeated without end. It is the highest emblem in the cipher of the world.”
—Ralph Waldo Emerson (1803–1882)