Class 5: Introduction to Modern Cryptography by Professor Avishek Adhikari, Presidency University

In this class I talked about the Basic Mathematics, mostly the part of Abstract Algebra that will be required for our course on Cryptography. I started with the intuitive idea of basic motivations for group theory through examples, such as (Z,+). Then I talked about the cyclic group (Z_n,+), one of the most important groups that will be used in studying Public Key Cryptography. We also discussed about Euler phi function and Extended Euclidean Algorithm, the group of Units, i.e, U_n, Fermat's Little Theore, Euler's Theorem. Mostly I follow my book (currently Chapter 10): Adhikari M R and Adhikari A: Basic Modern Algebra with Applications, Springer, 2014 Viewers are also requested to watch my following videos on Basic Group Theory to know more about basic group theory. https://www.youtube.com/playlist?list=PLxPYbPBbtwgIhqjWVcXuGYK8zoJk4LQAa