Book Image

Modern Cryptography for Cybersecurity Professionals

By : Lisa Bock
Book Image

Modern Cryptography for Cybersecurity Professionals

By: Lisa Bock

Overview of this book

In today's world, it is important to have confidence in your data storage and transmission strategy. Cryptography can provide you with this confidentiality, integrity, authentication, and non-repudiation. But are you aware of just what exactly is involved in using cryptographic techniques? Modern Cryptography for Cybersecurity Professionals helps you to gain a better understanding of the cryptographic elements necessary to secure your data. The book begins by helping you to understand why we need to secure data and how encryption can provide protection, whether it be in motion or at rest. You'll then delve into symmetric and asymmetric encryption and discover how a hash is used. As you advance, you'll see how the public key infrastructure (PKI) and certificates build trust between parties, so that we can confidently encrypt and exchange data. Finally, you'll explore the practical applications of cryptographic techniques, including passwords, email, and blockchain technology, along with securely transmitting data using a virtual private network (VPN). By the end of this cryptography book, you'll have gained a solid understanding of cryptographic techniques and terms, learned how symmetric and asymmetric encryption and hashed are used, and recognized the importance of key management and the PKI.
Table of Contents (16 chapters)
1
Section 1: Securing Our Data
5
Section 2: Understanding Cryptographic Techniques
9
Section 3: Applying Cryptography in Today's World

Dissecting block and stream ciphers

Symmetric encryption algorithms are flexible, in that they can encrypt data using a block or stream cipher. In this section, we'll compare the two and see why, in most cases, a stream cipher is the preferred method to encrypt data.

Let's start with a discussion on how a block cipher works.

Using a block cipher

A block cipher uses either a 64- or a 128-bit block of plaintext to produce a same-size block of ciphertext.

While this seems a simple way to encrypt data, we must keep in mind when using a block cipher that the block of data must be exactly the fixed-size requirement. Therefore, if encrypting data using a block size of 128 bits, the input must be 128 bits.

A block of data is rarely the exact size for a given encryption algorithm. As a result, if we need to encrypt 92 bits of data using a 128-bit block cipher, 32 bits of padding must be added. Too much padding during encryption will make the process inefficient...