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:
“All my life I have lived and behaved very much like [the] sandpiper—just running down the edges of different countries and continents, “looking for something” ... having spent most of my life timorously seeking for subsistence along the coastlines of the world.”
—Elizabeth Bishop (1911–1979)
“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)