A functional approach to encoding and decoding a cryptogram

• Main Authors: Canlas, Joselito P., Dequito, Joseph C.
• Format: text
• Language: English
• Published: Animo Repository 1996
• Subjects: Cryptography; Signs and symbols; Functions > Computer programs; Programming (Mathematics); Coding theory
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/16297
• Institution: De La Salle University

This thesis presents an application of functions and their inverses in encoding and decoding a cryptogram. The process of transforming a message into its unintelligible form is known as encoding or encryption. On the other hand, the reverse process of converting the encoded message back into its original form is known as decoding process. A function is utilized to encode a message converted into its ASCII values while the corresponding inverse function is applied to the encoded message to retrieve back the original message.The coding schemes illustrated in this study use four types of functions: linear functions, quadratic functions, linear modular arithmetic functions, and the exponential modular arithmetic functions. All of the concepts used in this study are based on the results given by James Reagan in his article entitled Get the Message? Cryptograph, Mathematics and Computers . The article does not include any mathematical definitions but only describes each coding scheme by showing how it is manipulated. The researchers provided the required definitions and concepts from Number Theory and also discussed each coding scheme derived from the function and its inverse.