This week’s activity had students exploring cryptology with an activity to encode and decode messages using the Caesar cipher and Vignenère cipher. Although our computers don’t use a Caesar or Vignenère cipher, this activity helped students to start thinking about security and encryption.
Can YOU crack this ciphertext?
Fdurqghohw
One of the earliest and simplest attempts at encryption is the Caesar cipher, employed by Julius Caesar in the 1st century BC. This schema is known as a substitution cipher because it substitutes each letter of the original, unencrypted message (called the plaintext) with a corresponding letter in the final, encrypted message (called the ciphertext).
The Caesar cipher works by aligning two alphabets against one another and offsetting them by a number of positions. Caesar, himself, used a “left rotation” of three spaces, causing an
a of the plaintext to align with an x in the ciphertext. (Edhesive.com)