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:
“The shallowest still water is unfathomable. Wherever the trees and skies are reflected, there is more than Atlantic depth, and no danger of fancy running aground.”
—Henry David Thoreau (1817–1862)
“Sunshine of late afternoon—
On the glass tray
a glass pitcher, the tumbler
turned down, by which
a key is lying—And the
immaculate white bed”
—William Carlos Williams (1883–1963)
“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)