A+ grade for matrices/ coding investigation. Stage 1 Specialist Mathematics. Introduction: Security of information is of major interest to many corporations and government throughout the world, especially with respect to the military and economic information. Many different ciphers have been developed over the years such as Four Square, Bifid, Trifid, Playfair and Hill to name a few. Playfair cipher, a symmetric encryption technique, was popularized in 2007 in the movie “National Treasure 2- The Book of Secrets”. However, this cipher is no longer considered useful by military organisations due to the ease and speed by which it can be decoded by the computers. In this task you will use matric multiplication and modular mathematics (mod maths) to code and decipher a message. You will use the principles modelled to design and use your own encryption key. It will be important to note the limitations of the simplified method of encryption. Matric multiplications encryption steps are still used today in combination with non-linear encryption steps to create secure ciphers.