I am reading this page on wikipedia on Key derivation function here where it states:
In cryptography, a key derivation function (KDF) is a cryptographic algorithm that derives one or more secret keys from a secret value such as a main key, a password, or a passphrase using a pseudorandom function (which typically uses a cryptographic hash function or block cipher)
I am curious about the part that states:
using a pseudorandom function (which typically uses a cryptographic hash function or block cipher)
This kind of implies that PRFs could be block cipher. Is this correct? As I assumed that PRP (pseudorandom permutations) are the ones that could be block ciphers.
Is my understanding wrong? Or the Wiki entry wrong?