Book Image

Cryptography Algorithms

By : Massimo Bertaccini
Book Image

Cryptography Algorithms

By: Massimo Bertaccini

Overview of this book

Cryptography Algorithms is designed to help you get up and running with modern cryptography algorithms. You'll not only explore old and modern security practices but also discover practical examples of implementing them effectively. The book starts with an overview of cryptography, exploring key concepts including popular classical symmetric and asymmetric algorithms, protocol standards, and more. You'll also cover everything from building crypto codes to breaking them. In addition to this, the book will help you to understand the difference between various types of digital signatures. As you advance, you will become well-versed with the new-age cryptography algorithms and protocols such as public and private key cryptography, zero-knowledge protocols, elliptic curves, quantum cryptography, and homomorphic encryption. Finally, you'll be able to apply the knowledge you've gained with the help of practical examples and use cases. By the end of this cryptography book, you will be well-versed with modern cryptography and be able to effectively apply it to security applications.
Table of Contents (15 chapters)
1
Section 1: A Brief History and Outline of Cryptography
3
Section 2: Classical Cryptography (Symmetric and Asymmetric Encryption)
7
Section 3: New Cryptography Algorithms and Protocols
12
Section 4: Homomorphic Encryption and the Crypto Search Engine

Quantum Fourier Transform

Let's discover a little bit more about the Fourier Transform (FT) and QFT.

FT is a mathematical function. It can be intuitively thought of like a musical chord in terms of volume and frequency. The FT can transform an original function into another function, representing the amount of frequency present in the original function. The FT depends on the spatial or temporal frequency and is referred to as a time domain. It is represented by a graphic that shows the frequency that was detected, as shown in the following diagram:

Figure 8.14 – Fourier Transform

Figure 8.14 – Fourier Transform

To understand how this works, let's look at an example of FT taking an arithmetic succession of numbers, like so:

1, 3, 7, 2, 1, 3, 7, 2

As you can see, we have the first four numbers – 1, 3, 7, 2 – which get repeated two times. In other words, we can break the succession into two parts:

1,3,7,2 | 1,3,7,2

Note

The | symbol represents...