chapter nine

9. Secure transport

 

This chapter covers:

  • Secure transport protocols, protocols used to encrypt communications between machines.
  • The Transport Layer Security (TLS) protocol, the most widely used secure transport protocol.
  • The Noise protocol framework, a modern alternative to TLS.

The heaviest use of cryptography today is most probably to encrypt communications. After all, cryptography was invented for this purpose. To do this, applications generally do not make use of cryptographic primitives (like authenticated encryption) directly, but instead use much more involved protocols that abstract the use of the cryptographic primitives. I call these protocols "secure transport" protocols, for lack of a better term.

In this chapter you will learn about the most widely-used secure transport protocol: the Transport Layer Security (TLS) protocol. I will also lightly cover other secure transport protocols and how they differ from TLS.

9.1 The SSL and TLS secure transport protocols

In order to understand why transport protocols are a thing, let’s walk through a motivating scenario.

9.1.1 From SSL to TLS

9.1.2 Using TLS in practice

9.2 How does the TLS protocol work?

9.2.1 The TLS handshake

9.2.2 How TLS 1.3 encrypts application data

9.3 The state of the encrypted web today

9.4 Other secure transport protocols

9.5 The Noise protocol framework: a modern alternative to TLS

9.5.1 The many handshakes of Noise

9.6 A handshake with Noise

9.6 Summary