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

21

Attacks on the TLS Record Protocol

In the previous chapter, we learned about attacks on the TLS Handshake protocol. Those attacks exploit either protocol-level weaknesses – as in the case of the triple handshake or TLS downgrade attacks – or the existence of padding oracles that allow Mallory to extract the TLS pre-shared key.

In this chapter, we study attacks on the TLS Record protocol. Among other things, you will learn the following:

  • How the timing of the messages coming from Alice, the TLS server, can be used to create a padding oracle similar to the one we discussed in the previous chapter (albeit targeting the TLS Record protocol)

  • How predictable initialization vectors can be used to attack the CBC mode of operation

  • How lossless data compression can undermine the security of an encryption scheme even if the scheme itself is cryptographically secure

Upon completing this chapter, you will have a good overview and good understanding of the attacks targeting the TLS...