Book Image

TLS Cryptography In-Depth

By : Dr. Paul Duplys, Dr. Roland Schmitz
Book Image

TLS Cryptography In-Depth

By: Dr. Paul Duplys, Dr. Roland Schmitz

Overview of this book

TLS is the most widely used cryptographic protocol today, enabling e-commerce, online banking, and secure online communication. Written by Dr. Paul Duplys, Security, Privacy & Safety Research Lead at Bosch, and Dr. Roland Schmitz, Internet Security Professor at Stuttgart Media University, this book will help you gain a deep understanding of how and why TLS works, how past attacks on TLS were possible, and how vulnerabilities that enabled them were addressed in the latest TLS version 1.3. By exploring the inner workings of TLS, you’ll be able to configure it and use it more securely. Starting with the basic concepts, you’ll be led step by step through the world of modern cryptography, guided by the TLS protocol. As you advance, you’ll be learning about the necessary mathematical concepts from scratch. Topics such as public-key cryptography based on elliptic curves will be explained with a view on real-world applications in TLS. With easy-to-understand concepts, you’ll find out how secret keys are generated and exchanged in TLS, and how they are used to creating a secure channel between a client and a server. By the end of this book, you’ll have the knowledge to configure TLS servers securely. Moreover, you’ll have gained a deep knowledge of the cryptographic primitives that make up TLS.
Table of Contents (30 chapters)
1
Part I Getting Started
8
Part II Shaking Hands
16
Part III Off the Record
22
Part IV Bleeding Hearts and Biting Poodles
27
Bibliography
28
Index

14.1 The big picture

In the last part of the book, we covered in detail the TLS Handshake protocol and the cryptography needed to implement the main security objectives of the TLS Handshake protocol, namely entity authentication and key agreement. For the latter of these goals, public-key cryptography was needed, for the former, we used both public-key cryptography, especially digital signatures, and symmetric cryptography, especially message authentication codes (MACs).

Figure 14.1: TLS subprotocols

Figure 14.1: TLS subprotocols

But entity authentication and key agreement are only prerequisites of the main goal of TLS, which is to establish a secure tunnel between client and server, providing confidentiality, integrity protection, and message authenticity. As already briefly discussed in Chapter 6, Transport Layer Security at a Glance, it is the task of the TLS Record protocol, located immediately above the transport layer (see Figure 14.1), to actually realize this tunnel. In order to do so, it...