---
title: "createCredentialAssertionRequest(challenge:)"
framework: authenticationservices
role: symbol
role_heading: Instance Method
path: "authenticationservices/asauthorizationsecuritykeypublickeycredentialprovider/createcredentialassertionrequest(challenge:)"
---

# createCredentialAssertionRequest(challenge:)

Creates an assertion request with a challenge.

## Declaration

```swift
func createCredentialAssertionRequest(challenge: Data) -> ASAuthorizationSecurityKeyPublicKeyCredentialAssertionRequest
```

## Parameters

- `challenge`: A stream of bytes that the server provides to prove an authenticator is valid.

## Return Value

Return Value A security key credential registration request.

## See Also

### Creating the request

- [relyingPartyIdentifier](authenticationservices/asauthorizationsecuritykeypublickeycredentialprovider/relyingpartyidentifier.md)
- [createCredentialRegistrationRequest(challenge:displayName:name:userID:)](authenticationservices/asauthorizationsecuritykeypublickeycredentialprovider/createcredentialregistrationrequest(challenge:displayname:name:userid:).md)