Author: K Z

Public Key Cryptography Unlike symmetric key cryptography, we do not find historical use of public-key cryptography. It is a relatively new concept. Symmetric cryptography was well suited for organizations such…

In this chapter, we will discuss the different modes of operation of a block cipher. These are procedural rules for a generic block cipher. Interestingly, the different modes result in…

The more popular and widely adopted symmetric encryption algorithm likely to be encountered nowadays is the Advanced Encryption Standard (AES). It is found at least six time faster than triple…

In this section, we will discuss Triple DES. The speed of exhaustive key searches against DES after 1990 began to cause discomfort amongst users of DES. However, users did not…

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…