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

10

Digital Certificates and Certification Authorities

In the previous two chapters, we discussed the nuts and bolts of public key cryptography and digital signatures. In the current chapter, we delve into the details of the infrastructure needed to verify the authenticity of public keys. We will see that digital signatures play an important part in this: digital certificates are digitally signed documents, where a trusted third party warrants that a public key belongs to a certain entity, whereas certificate authorities are the entities responsible for issuing certificates. More precisely, we will look at so-called X.509 certificates including the following:

  • Data fields

  • Enrollment

  • Revocation

  • Trust model

After describing the format of a digital certificate and the processes needed to issue and verify a certificate in general, we turn to RFC 8446 and describe the usage of certificates and certificate authorities within TLS. Here, you will learn the following:

  • What TLS extensions look...