---
title: "deriveKey(inputKeyMaterial:salt:info:output:)"
framework: cryptokit
role: symbol
role_heading: Type Method
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+, watchOS 27.0+]
path: "cryptokit/hkdf/derivekey(inputkeymaterial:salt:info:output:)"
---

# deriveKey(inputKeyMaterial:salt:info:output:)

Derives a symmetric encryption key from a main key or passcode using HKDF key derivation with information and salt you specify.

## Declaration

```swift
static func deriveKey(inputKeyMaterial: SymmetricKey, salt: RawSpan? = nil, info: RawSpan? = nil, output outputKey: inout OutputRawSpan)
```

## Parameters

- `inputKeyMaterial`: The main key or passcode the derivation function uses to derive a key.
- `salt`: The salt to use for key derivation.
- `info`: The shared information to use for key derivation.
- `outputKey`: An output span that will be populated with the derived symmetric key.