diff --git a/book/source/03-cryptography.md b/book/source/03-cryptography.md
index f26e32e..5658494 100644
--- a/book/source/03-cryptography.md
+++ b/book/source/03-cryptography.md
@@ -29,14 +29,14 @@ It is derived from the original message using a (symmetric) secret key. The reci
 
 [HMAC](https://en.wikipedia.org/wiki/HMAC) is a type of MAC that relies on a hash function. It is used in the OpenPGP protocol.
 
-### Key Derivation Functions
+### Key derivation functions
 
-Hash functions can also be used to construct [key derivation functions](https://en.wikipedia.org/wiki/Key_derivation_function) (KDF).
-Those can for instance be used to derive symmetric key material from a password by repeatedly feeding it through a hash function.
+A hash function can also be used to create a [key derivation function](https://en.wikipedia.org/wiki/Key_derivation_function) (KDF).
+One application of KDFs is to generate symmetric key material from a password by iteratively passing it through a hash function.
 
-A prominent example of a KDF which is relevant for the OpenPGP specification is the so-called [HKDF](https://en.wikipedia.org/wiki/HKDF) which is a key derivation function based on the HMAC message authentication code.
+A notable KDF for the OpenPGP specification is the [HKDF](https://en.wikipedia.org/wiki/HKDF), which is a key derivation function based on the HMAC.
 
-More information on KDFs and their use in the OpenPGP protocol can be found in chapters [5](encrypted_secrets) and 10 (SEIPDv2).
+For detailed information on KDFs and their role in the OpenPGP protocol, see the [encrypted secrets](encrypted_secrets) chapter and the [SEIPDv2](SEIPDv2) section of the encryption chapter.
 
 ## Symmetric-key cryptography