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)
“Now narrow minds can develop as well through persecution as through benevolence; they can assure themselves of their power by tyrannizing cruelly or beneficently over others; they go the way their nature guides them. Add to this the guidance of interest, and you will have the key to most social riddles.”
—Honoré De Balzac (1799–1850)
“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)