ABSTRACT
The history of cryptography starts from the ancient era when it was practiced by the secret societies or by the troops on the battlefield.
Keywords 11 2.1 Caesar Cipher 12
2.1.1 Algorithm 12 2.1.2 Implementation 13 2.1.3 Limitations 15
2.2 Monoalphabetic Cipher 15 2.2.1 Algorithm 15 2.2.2 Implementation 16 2.2.3 Limitations 18
2.3 Playfair Cipher 19 2.3.1 Algorithm 19 2.3.2 Implementation 20 2.3.3 Limitations 27
2.4 Polyalphabetic Cipher 27 2.4.1 Algorithm 29 2.4.2 Implementation 29 2.4.3 Limitations 33
The necessity of such an approach has increased with time. In the current information era, there is indeed no time at which information security is not necessary, and hence cryptography. From military to civilian, or from government to individual, information security is tremendously necessary. Consequently, several algorithms are proposed, and they are implemented with various hardware. In this chapter, we discuss a couple of renowned classical encryption techniques.
