Write a brief history of steganography.

What will be an ideal response?

ANSWER: Steganography has been used since ancient times. Greek rulers used this technique to send covert messages to diplomats and troops via messengers. To hide messages, rulers shaved their messengers’ heads and tattooed messages on their scalps. After the messengers's hair grew enough to cover the message, they left for their destinations, where they shaved their heads so that recipients could read the message. This method was a clever way to send and retrieve encrypted information, but it was inefficient because the messengers’ hair took a long time to grow back, and only a limited amount of space was available to write messages. However, it enabled the Greeks to send secret messages until their enemies discovered this early form of steganography and began intercepting messengers.