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

7.12 Summary

In this chapter, we introduced the mathematical foundations of public-key cryptosystems and looked in detail at the two most important examples, the Diffie-Hellman key exchange protocol and the RSA cryptosystem. We also investigated how exactly public-key cryptography is used within TLS.

By now, you should be aware of a very substantial difference between Diffie-Hellman and RSA: while RSA has to work with integers, the Diffie-Hellman protocol works in principle with any abelian group 𝔾. The difficulty of the discrete logarithm problem, which lies at the core of the Diffie-Hellman protocol, varies from group to group. If we can find a group where it is especially difficult, the corresponding key lengths could be shorter in that group. This fact is what makes elliptic curves so attractive in modern cryptography. They are the topic of our next chapter.