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:
“He’s like an express train running through a tunnel—one shriek, sparks, smoke and gone.”
—Virginia Woolf (1882–1941)
“The knight slew the dragon,
The lady was gay,
They rode on together,
Away, away.”
—Unknown. This Is the Key (l. 38–41)
“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)