Cryptography

The Data Encryption Standard (DES) is a symmetric-key block cipher published by the National Institute of Standards and Technology (NIST). DES is an implementation of a Feistel Cipher. It uses…

Feistel Cipher is not a specific scheme of a block cipher. It is a design model from which many different block ciphers are derived. DES is just one example of…

The basic scheme of a block cipher is depicted as follows − A block cipher takes a block of plaintext bits and generates a block of ciphertext bits, generally of…

Digital data is represented in strings of binary digits (bits) unlike alphabets. Modern cryptosystems need to process this binary strings to convert in to another binary string. Based on how…

In the second chapter, we discussed the fundamentals of modern cryptography. We equated cryptography with a toolkit where various cryptographic techniques are considered as the basic tools. One of these…

In the present era, not only business but almost all the aspects of human life are driven by information. Hence, it has become imperative to protect useful information from malicious…

A cryptosystem is an implementation of cryptographic techniques and their accompanying infrastructure to provide information security services. A cryptosystem is also referred to as a cipher system. Let us discuss a…

Modern cryptography is the cornerstone of computer and communications security. Its foundation is based on various concepts of mathematics such as number theory, computational complexity theory, and probability theory. Characteristics…

In This section, we will discuss the Origin of Cryptography. A human being from ages had two inherent needs − (a) to communicate and share information and (b) to communicate…