12.7 Summary
In this chapter, we took a detailed look at the TLS specification and the various secrets and keys it defines. Specifically, we have seen how different keys used for different contexts are derived from initial secrets – either PSKs or a secret coming from a Diffie-Hellman key exchange.
We have also tried to highlight various best practices in cryptography engineering deployed within TLS: different keys for different purposes, well-defined fallback and alert procedures in case of protocol errors, and the destruction of obsolete keying material.
In the next chapter, we will take a step back and see how the cryptographic primitives we discussed in the previous chapters fit together to form the TLS Handshake protocol.
