---
title: kdf
framework: cryptokit
role: symbol
role_heading: Instance Property
path: cryptokit/hpke/ciphersuite/kdf
---

# kdf

The key derivation function (KDF) for deriving the symmetric key.

## Declaration

```swift
let kdf: HPKE.KDF
```

## See Also

### Inspecting a cipher suite

- [aead](cryptokit/hpke/ciphersuite/aead.md)
- [kem](cryptokit/hpke/ciphersuite/kem.md)