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 juice on a letter.Three Lions/Getty Images Humans have had a long ...

For a long time, seeing those words pop up onscreen was the best indicator of good gossip to come. Close seconds included “OK, so…” for the more demure among us, or a simple teacup emoji for the ...

Putting secrets in texts is risky business. An email is almost certainly a no-go, as is a traditional SMS. Encrypted texting, like iMessage, is better, since only your device and the recipient’s can ...

Do you ever feel like someone is peering over your shoulder while sending private messages to your friends and family? Well, you won't have to worry about those nosy people knowing what you're sending ...

A ninja history student in Japan sent her education into stealth mode when she turned in a seemingly blank paper for her term essay. Eimi Haga wrote the essay with invisible ink. Haga told the BBC ...