Encryption Project

Encryption is the ability to transmit information in a form that is unreadable to anyone other than the intended recipients. Cryptography, which has been in use for thousands of years, is the use of codes and ciphers to protect information. Until the development of computer systems, encryption was performed with pen and paper. In more recent times, the advances in technology have allowed for much more advanced and complex systems of encoding.

For this project you are tasked with developing a MATLAB program which is a monoalphabetic cipher for encryption purposes. A monoalphabetic cipher uses the same substitution across an entire message. For example, if the letter A is encrypted as the letter R, that will hold true for the entire message.

Many political campaigns and professional careers have been tarnished by a misdirected or exposed Tweet. The purpose of the program developed for this project is to encrypt 140 character Twitter message so that only those with whom you have shared your cipher will be able to read your Tweets.

Requirements:

• You must use all 26 English alphabet characters, a space, and numbers 0-9. If you wish, you may assume all letters are lowercase. Other punctuation or special characters are encourages, but not required.

• You must develop your own letter to number substitution or cipher. You must submit a “decoding key” in tabular format in your technical report so that one can decipher your message.

• Your code needs to requires the user to input the either the message to be ciphered or deciphered

• The command window must only display the initial text, the encrypted message and the decoded message, and any user input requests.

Helpful Tips:

• Convert the string message to the numerical equivalent vector

• Reshape the vector into a message matrix 10 x 14

• Create an encoding matrix (must have the same number of columns as the message matrix has rows and must be invertible)

• Multiply the encoding matrix by the converted string matrix to create the encoded message

• Display the encoded message, this is the message that would be transmitted

• Create a decoding matrix by inverting the encoding matrix

• Multiply the encoded matrix by the decoded matrix

• Change the numbers back to string values and display the string message

• Display the decoded message