---
title: challenge
framework: authenticationservices
role: symbol
role_heading: Instance Property
path: authenticationservices/asauthorizationpublickeycredentialregistrationrequest/challenge
---

# challenge

Arbitrary data that the client signs as proof of a valid registration or attestation.

## Declaration

```swift
var challenge: Data { get set }
```

## See Also

### Getting the properties

- [attestationPreference](authenticationservices/asauthorizationpublickeycredentialregistrationrequest/attestationpreference.md)
- [displayName](authenticationservices/asauthorizationpublickeycredentialregistrationrequest/displayname.md)
- [name](authenticationservices/asauthorizationpublickeycredentialregistrationrequest/name.md)
- [relyingPartyIdentifier](authenticationservices/asauthorizationpublickeycredentialregistrationrequest/relyingpartyidentifier.md)
- [userID](authenticationservices/asauthorizationpublickeycredentialregistrationrequest/userid.md)
- [userVerificationPreference](authenticationservices/asauthorizationpublickeycredentialregistrationrequest/userverificationpreference.md)