For almost as long as people have been writing, people have wanted to protect what was written. According to some scholars, cryptography can be traced all the way back to 1900 BC, when the tomb of Khnumhotep II used unknown hieroglyphs to apparently mask the intent of a carved message. Other early messages include simple ciphers on Mesopotamian clay tablets and the Greek use of a “scytale,” a decoding stick, which would reveal a message when a strip of cloth with a cipher on it was wrapped around it.
