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:
“And this our life, exempt from public haunt,
Finds tongues in trees, books in the running brooks,
Sermons in stones, and good in everything.”
—William Shakespeare (1564–1616)
“The knight slew the dragon,
The lady was gay,
They rode on together,
Away, away.”
—Unknown. This Is the Key (l. 38–41)
“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)