Introduction to cryptography

Cryptography is the practice of studying and implementing techniques that lead to secure communication. When cryptography is correctly deployed, we accomplish four major requirements:

• Confidentiality
• Integrity
• Authenticity
• Non-repudiation

Each of these requirements has its own goals. Let's understand each of them.

Integrity

Can the receiver be confident that the original message that was sent by the sender is the same that he has received? In short, the message has not been modified. Here is an example problem statement:

Sent Message --> "Schedule Launch Date : 27 June 2017 "
Received Message --> "Schedule Launch Date : 29th June 2017"

In the previous message, we...