Early uses of cryptography

For thousands of years, we have been trying to conceal private information in a variety of ways. Today, we use cryptographic techniques to protect credit card information, personally identifiable information (PII), and online transactions. However, over the years, much of the effort to protect information has stemmed from activity surrounding war efforts. Concealing information was done in an attempt to prevent the enemy from gaining access to sensitive information.

In this section, we'll take a look at some ancient ways to hide messages. We'll start with a few of the early examples used, which includes the scytale and even tattoos. We'll also review monoalphabetic ciphers, such as the Caesar cipher. We'll then review the introduction of polyalphabetic ciphers, using the Vigenère cipher as an example.

Let's start with a brief look at some ancient ways to conceal information.

Using tattoos and scytales

Early iterations...