Invisible ink was known as "sympathetic stain" during the Revolutionary War. By any name, it was an effective spying tool.

A spy-inspired system of secret messages plays into the show’s central theme of an identity in flux. The title cards for British actor Riz Ahmed’s new dramedy, Bait, are a colorful explosion of ...

BOSTON — The information needed to decipher the last remaining unsolved secret message embedded within a sculpture at CIA headquarters in Virginia sold at auction for nearly $1 million, the auction ...