---
title: second
framework: authenticationservices
role: symbol
role_heading: Instance Property
path: authenticationservices/asauthorizationpublickeycredentialprfassertionoutput-swift.struct/second
---

# second

A second symmetric key that’s unique to the passkey, and derives from the second input, if specified.

## Declaration

```swift
let second: SymmetricKey?
```

## Discussion

Discussion If input2 isn’t specified, this key is nil.

## See Also

### Accessing symmetric keys

- [first](authenticationservices/asauthorizationpublickeycredentialprfassertionoutput-swift.struct/first.md)