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:

    Of all the thirty-six alternatives, running away is best.
    Chinese proverb.

    The key to the age may be this, or that, or the other, as the young orators describe; the key to all ages is—Imbecility: imbecility in the vast majority of men, at all times, and even in heroes, in all but certain eminent moments: victims of gravity, customs and fear. This gives force to the strong,—that the multitude have no habit of self-reliance or original action.
    Ralph Waldo Emerson (1803–1882)

    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)