- Version
- Download 21
- File Size 862.47 KB
- File Count 1
- Create Date December 11, 2019
- Last Updated February 9, 2020
Education for all
The word cryptography has come from a Greek word, which means secret writing. In the present day context, it refers to the tools and techniques used to make messages secure for communication between the participants and make messages immune to attacks by hackers. For private communication through a public network, cryptography plays a very crucial role. The role of cryptography can be illustrated with the help of a simple model of cryptography as shown in Fig. 8.1.1. The message to be sent through an unreliable medium is known as plaintext, which is encrypted before sending over the medium. The encrypted message is known as ciphertext, which is received at the other end of the medium and decrypted to get back the original plaintext message. In this lesson, we shall discuss various cryptography algorithms, which can be divided into two broad categorize - Symmetric key cryptography and Public key cryptography.