In cryptography, a key signature is the result of a third-party applying a cryptographic signature to a representation of a cryptographic key. This is usually done as a form of assurance or verification: If "Alice" has signed "Bob"'s key, it can serve as an assurance to another party, say "Eve", that the key actually belongs to Bob, and that Alice has personally checked and attested to this.
The representation of the key that is signed must necessarily be shorter than the key itself, because most public-key signature schemes can only encrypt or sign short lengths of data. Some derivative of the public key fingerprint may be used.
Famous quotes containing the words key and/or signature:
“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)
“The childless experts on child raising also bring tears of laughter to my eyes when they say, “I love children because they’re so honest.” There is not an agent in the CIA or the KGB who knows how to conceal the theft of food, how to fake being asleep, or how to forge a parent’s signature like a child.”
—Bill Cosby (20th century)