Basic Cryptography and Programming with Crypto API (Coursera)

We will learn the Diffie-Hellman Symmetric Key Exchange Protocol to generate a symmetric key for two parties to communicate over insecure channel. We will learn the modular arithmetic and the Euler Totient Theorem to appreciate the RSA Asymmetric Crypto Algorithm, and use OpenSSL utility to realize the basic operations of RSA Crypto Algorithm. Armed with this knowledge, we learn how to use PHP Crypto API to write secure programs for encrypting and decrypting documents and for signing and verify documents. We then apply these techniques to enhance the registration process of a website which ensures the account created is actually requested by the owner of the email account.

Course 2 of 4 in the Fundamentals of Computer Network Security Specialization.

Syllabus

WEEK 1

Basic Cryptography

In this module we learn the basic concepts and principles of crytography, introduce the basic concept of cryptoanalysis using mono-alphabetic substitution cipher as an example, and discuss the one-time-pad and quantum key distribution concepts.

WEEK 2

Symmetric Key Cryptography

In this module we present the basic mechanism of symmetric key crytography algorithms, discuss the DES and AES standard, describe the criteria for selecting AES standard, present the block cipher operating modes and discuss how the block swapping attacks and replay attacks can be prevented and detected.

WEEK 3

Assymetric Key Cryptography

In this module we will learn the Diffie-Hellman Symmetric Key Exchange Protocol, the modular arithmetic, the Euler Totient Theorm, and RSA Asymmetric Crypto Algorithm, and use OpenSSL to realize the basic operations of RSA Crypto Algorithm.

Graded: Project 2b. Decipher the message encrypted with shared key established by the Diffie-Hellman Key Exchange Protocol

WEEK 4

Develop Secure Programs with Crypto API

In this module, we learn how to use Crypto API to write secure programs for encrypting and decrypting documents, and for signing and verify documents. We then apply the techniques to enhance the registration process of a website which ensures the account created is actually belonging to the owner of the email account the request profile.