Running Key Cipher

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:

    “Would you—be good enough—” Alice panted out, after running a little further, “to stop a minute—just to get—one’s breath again?”
    “I’m good enough,” the King said, “only I’m not strong enough. You see, a minute goes by so fearfully quick. You might as well try to stop a Bandersnatch!”
    Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)

    Power, in Case’s world, meant corporate power. The zaibatsus, the multinationals ..., had ... attained a kind of immortality. You couldn’t kill a zaibatsu by assassinating a dozen key executives; there were others waiting to step up the ladder; assume the vacated position, access the vast banks of corporate memory.
    William Gibson (b. 1948)

    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)