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 saw that the data has been tampered with.
Integrity denotes the way the receiver can be 100% confident that the message received has not been tampered with.
Authenticity
Can a receiver be confident that the message he received originates from the intended sender?
For example, Pavan received the following email...
