The Problem

Cryptography is the study of codes, the majority of which involve a great deal of mathematics, both simple and complex. Some of its major applications are protection of credit card numbers to prevent people from purchasing merchandise with random sixteen digit numbers, website based applications that gather information for orders, purchasing, and reservations, and military and national security matters. The objective of any good cryptography is to make it impossible, or at any rate extremely difficult and time-consuming, for anyone who intercepts the information to decipher it. The objective here is to detail the basics of cryptography and how to use matrices to encrypt and decrypt messages.

Background Information

• Historical information on the basics of cryptography and the Enigma Machine used by the Germans during World War II are included in the project.

Materials Included

Activites and full explanations for:

• Matrix multiplication
• Determinants and inverses of 2×2 and 3×3 matrices
• Cryptography using 2×2 and 3×3 matrices