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:

    ‘Tis with my mind
    As with the tide swelled up unto his height,
    That makes a still-stand, running neither way.
    William Shakespeare (1564–1616)

    They have thrown away her electric toothbrush, someone else slips
    The key into the lock of her safety-deposit box
    At the Crocker-Anglo Bank; her seat at the cricket matches
    Is warmed by buttocks less delectable than hers.
    Randall Jarrell (1914–1965)

    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)