A writer for Inc has quoted me in an article called “New Ways to Keep Hackers Out of Your Business”

While you might think of encryption as something we’ve been using only since the advent of computers, it’s really a rather old practice. “Encryption is based upon a secret,” says Davi Ottenheimer, expert on the Focus network and founder of San Francisco-based security consulting firm flyingpenguin, who likes to cite Julius Caesar and Thomas Jefferson as examples of historical figures who have hidden things by using cryptography.

Caesar used a substitution cipher to communicate with his generals that involved replacing the letters in a message with a shifted alphabet. For instance, a shift of three would make all the As in message Ds; Bs would become Es, and so forth.

Jefferson used a type of wheel cipher during the Revolutionary War that involved 36 disks stacked on an axle, each with a different version of a scrambled alphabet on the outer edge. When both the sender and receiver had the numbered disks in the same order and rotated them in the right way, an understandable message would appear.

“People have historically improved encryption during times of conflict or war,” Ottenheimer says. “It’s all about secrecy, really, confidentiality. It doesn’t require super-sophisticated technology as much as it requires people being fairly intelligent about how they can keep a secret.”