Add Yahoo as a preferred source to see more of our stories on Google. William Abel, a mail censor at Iowa's State Prison, Fort Madison, using a hot iron to bring out a secret message written in lemon ...

In steganography, an ordinary message masks the presence of a secret communication. Humans can never do it perfectly, but a new study shows it’s possible for machines. On June 27, 2010, the FBI ...

Secret messages can be hidden inside fake conversations generated by AI chatbots. The technique could give people a way to communicate online without arousing the suspicion of oppressive governments.

Vlogger Reuben Levine tells the story of the Colombian army in 2010 sending a message to prisoners of a revolutionary guerilla group by hiding a Morse code message in a concocted pop song. Watch this ...