Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying TLS Cryptography In-Depth
  • Table Of Contents Toc
  • Feedback & Rating feedback
TLS Cryptography In-Depth

TLS Cryptography In-Depth

By : Dr. Paul Duplys, Dr. Roland Schmitz
4.8 (4)
close
close
TLS Cryptography In-Depth

TLS Cryptography In-Depth

4.8 (4)
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)
close
close
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

22.2 FREAK

FREAK stands for Factoring RSA Export Keys. The attack was discovered in 2017 ([27]) and can be seen as a variant of the cipher suite downgrade attack shown in Figure 20.1 with respect to RSA as a key establishment mechanism. It works if server Alice supports weak, export-grade RSA cipher suites. Interestingly, client Bob may even support only strong RSA cipher suites for the attack to work.

More specifically, in the FREAK attack, Mallory modifies the cipher suite list sent by the client to be

A = TLSRSAEXPORTWITHDES40CBCSHA w

and forwards it to the server.

If the server accepts this cipher suite and sends a corresponding ServerHello back, Mallory modifies it to a stronger, non-export RSA cipher suite, as follows:

A1 = TLSRSAWITH3DESEDECBCSHA

The client now ought to use the strong RSA public key contained in the server’s certificate for securely transporting PreMasterSecret to the server. However, along with its certificate, the server also sends a ServerKeyExchange message containing an ephemeral export-grade RSA public...

Unlock full access

Continue reading for free

A Packt free trial gives you instant online access to our library of over 7000 practical eBooks and videos, constantly updated with the latest in tech

Create a Note

Modal Close icon
You need to login to use this feature.
notes
bookmark search playlist font-size

Change the font size

margin-width

Change margin width

day-mode

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Delete Bookmark

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Delete Note

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Edit Note

Modal Close icon
Write a note (max 255 characters)
Cancel
Update Note

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY