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:
“These six things doth the Lord hate: yea, seven are an abomination unto him: A proud look, a lying tongue, and hands that shed innocent blood, an heart that deviseth wicked imaginations, feet that be swift in running to mischief, a false witness that speaketh lies, and he that soweth discord among brethren.”
—Bible: Hebrew Proverbs 6:16-19.
“Yes, I know.
Death sits with his key in my lock.
Not one day is taken for granted.
Even nursery rhymes have put me in hock.”
—Anne Sexton (1928–1974)
“The eye is the first circle; the horizon which it forms is the second; and throughout nature this primary figure is repeated without end. It is the highest emblem in the cipher of the world.”
—Ralph Waldo Emerson (1803–1882)