--- url: 'https://www.corbado.com/blog/parallels-passkeys-cda' title: 'Parallels Passkeys: Testing Cross Device Authentication on Windows 11 VM on a Mac' description: 'Learn how to set up and test Cross-Device Authentication (CDA) via passkeys on Windows 11 VM using Parallels on Mac with external Bluetooth adapter.' lang: 'en' author: 'Vincent Delitz' date: '2024-09-20T11:20:39.399Z' lastModified: '2026-03-25T10:00:42.601Z' keywords: 'Parallels, Virtual Machine, VM' category: 'WebAuthn Know-How' --- # Parallels Passkeys: Testing Cross Device Authentication on Windows 11 VM on a Mac ## Key Facts - **Parallels built-in Bluetooth** cannot enable passkey Cross-Device Authentication on a Windows 11 VM: the Mac's native Bluetooth adapter is incompatible with this flow. - An **external USB Bluetooth 5.0 adapter** (such as the ASUS USB-BT500) is required to enable CDA via passkeys on a Parallels Windows 11 VM. - The adapter must be **assigned to the VM in Parallels Desktop Preferences** and the VM restarted before Windows can detect and install the necessary drivers. - **Windows 10 CDA testing** is not reliably possible via Parallels: real physical Windows 10 hardware is required for accurate results. - The most critical passkey CDA test flow to validate is **Android or iPhone authenticating into a Windows environment**. ## 1. Introduction When developing passkey authentication, one of the key components is testing cross-device authentication (CDA) via [QR code](https://www.corbado.com/blog/qr-code-login-authentication). While the operating system handles the core functionality, various dialogs and additional steps might be required, such as prompting users to create a local passkey after completing cross-device authentication. These differences result in variations in the flow that must be tested. The **most important test flow is Android / iPhone -> Windows**. Of course, final testing should be carried out with real [Windows 11](https://www.corbado.com/blog/passkeys-windows-11) devices but during development, Parallels Virtualization is often used on a macOS devices. **Parallels passkey CDA testing on Mac** How does Cross-Device Authentication (CDA) via passkeys work when testing on Parallels, specifically on a [Windows 11](https://www.corbado.com/blog/passkeys-windows-11) virtual machine running on a Mac? Let’s find out how this can be done, because at the moment the Parallels implementation [does not work](https://forum.parallels.com/tags/passkeys/) with passkey CDA. ## 2. Setting Up the Testing Environment Before you begin Cross-Device Authentication (CDA) with passkeys on a [Windows 11](https://www.corbado.com/blog/passkeys-windows-11) / Parallels running on a Mac, you'll need to set up the environment properly. Here's a step-by-step guide to getting started: ### 2.1 Installing Parallels with Windows 11 If you haven't already installed Windows 11 on Parallels, you'll need to do so. Note that installing Windows 10 is no longer feasible due to the lack of ARM builds. Parallels only supports Windows 11 on Macs with Apple Silicon (M1/M2). Windows 11 is automatically available in case you have a license accessible. ### 2.2 External Bluetooth Adapter **Using the macOS Bluetooth Adapter does not work.** Therefore, to test CDA via passkeys, an external Bluetooth 5.0 adapter is necessary, as Parallels cannot use the Mac's built-in Bluetooth for this functionality. Here's what you need: - **Adapter:** Purchase a standard USB Bluetooth adapter, such as the ASUS USB-BT500. - **USB to USB-C Adapter:** Since most USB Bluetooth adapters do not support USB-C, you'll need a USB to USB-C adapter to connect it to your Mac. ### 2.3 Connecting and Configuring the Adapter Follow these steps to set up the Bluetooth adapter for use with the Windows 11 VM: 1. **Plug in the Bluetooth Adapter**: Insert the Bluetooth adapter into the USB-C adapter and then plug it into your Mac. 2. **Allow Connection**: When macOS prompts you, allow the connection to the external Bluetooth device. 3. **Assign the Adapter to the VM**: - Open Parallels. Then, navigate to **Parallels Desktop Preferences**. ![parallels desktop preferences](https://www.corbado.com/website-assets/parallels_desktop_preferences_02eef6a59a.png) - In the Preferences window, assign the Bluetooth adapter to the Windows 11 VM to ensure it is always available when the VM is running. 4. **Restart the Windows 11 VM**: After assigning the adapter, restart the VM so it can properly detect and install the necessary drivers for the adapter. ### 2.4 Allow Bluetooth Access on Mac The first time the Windows VM tries to access the Bluetooth adapter, macOS might prompt you to confirm this action. Be sure to allow the access so that the Bluetooth adapter can work correctly within the VM and click “Always Allow”: ![allow parallels access to external bluetooth adapter](https://www.corbado.com/website-assets/Allow_USB_d2c7c80b1e.png) Once these steps are completed, your Windows 11 VM will be equipped to perform the Bluetooth-based cross-device authentication necessary for [passkey testing](https://www.corbado.com/blog/testing-passkeys). [Watch on YouTube](https://www.youtube.com/watch?v=0hRYXHESA24) ## 3. Test Cross-Device Authentication (CDA) Flow If you want to quickly check if your CDA Authentication works go ahead and use the [Passkeys Debugger](https://www.passkeys-debugger.io/). 1. Take out your mobile phone and navigate to [https://www.passkeys-debugger.io](https://www.passkeys-debugger.io). [Create a passkey](https://www.corbado.com/blog/passkey-creation-best-practices) with default settings: ![test cross device authentication debugger](https://www.corbado.com/website-assets/test_cross_device_authentication_debugger_dae17c14c6.png) 2. Open your Windows 11 Chrome with an Incognito tab, and switch from **Passkey Creation** to **Passkey Login** Tab and hit **Start Passkey Login** ![windows hello cda test](https://www.corbado.com/website-assets/windows_hello_cda_test_eefae3358c.png) 3. Choose “iPhone, iPad or [Android](https://www.corbado.com/blog/how-to-enable-passkeys-android) device” ![qr code testing webauthn](https://www.corbado.com/website-assets/qr_code_testing_webauthn_a6df605465.png) 4. Once you scan the [QR code](https://www.corbado.com/blog/qr-code-login-authentication) you will see that the devices are connected ![windows hello connection confirmation](https://www.corbado.com/website-assets/windows_hello_connection_confirmation_f744b3b86b.png) 5. On your mobile device, you will be able to select the created passkey ![face id passkey list](https://www.corbado.com/website-assets/face_id_passkey_list_7a3869e0e1.png) 6. Once the passkey ceremony is completed, you can see the results in the passkey debugger. Here is the link to our [test](https://www.passkeys-debugger.io/?options=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%3D). ![cda parsed assertion response](https://www.corbado.com/website-assets/cda_parsed_assertion_response_1417d05401.png) As you can see below, the `authenticatorAttachment` is set to cross-platform, we successfully completed a CDA on our Windows 11 VM. ## 4. Conclusion Testing Cross-Device Authentication (CDA) with passkeys on a Windows 11 virtual machine running on Parallels is possible, but it requires some additional hardware setup. While Parallels provides a good environment for [platform authenticator](https://www.corbado.com/glossary/platform-authenticator) testing, the CDA process will not work out-of-the-box due to the limitations of the Mac’s built-in Bluetooth. So the question **How does Cross-Device Authentication (CDA) via passkeys work when testing on Parallels, specifically on a Windows 11 virtual machine running on a Mac?** was answered in the blog post. To enable Cross-Device Authentication (CDA) via passkeys on a Windows 11 VM in Parallels, **an external USB Bluetooth adapter is essential**. Parallels cannot leverage the Mac's internal Bluetooth functionality for this purpose, so using a Bluetooth adapter (such as the ASUS USB-BT500) is the critical step to get everything working. By following the setup instructions for the adapter and testing the passkey flows, you can successfully complete CDA within a Windows 11 VM, confirming the system’s ability to handle cross-device authentication. From our experience it is especially important to test also Windows 10 environments, at the moment this is reliably only possible with real Windows 10 systems. Special thanks to [Christopher Harrell](https://www.linkedin.com/in/cnhcnh/) for pointing us to the the right solution within [FIDO Alliance](https://www.corbado.com/glossary/fido-alliance). ## Frequently Asked Questions ### Why doesn't passkey cross-device authentication work out of the box on Parallels? Parallels cannot use the Mac's built-in Bluetooth adapter for passkey Cross-Device Authentication. This is a fundamental limitation of the virtualization layer, meaning CDA via QR code will fail unless an external Bluetooth adapter is connected and assigned to the VM. ### What hardware do I need to test passkey CDA on a Windows 11 Parallels VM? You need a USB Bluetooth 5.0 adapter such as the ASUS USB-BT500 and a USB to USB-C adapter to connect it to a modern Mac. Once plugged in, the adapter must be assigned to the Windows 11 VM in Parallels Desktop Preferences and macOS must be set to always allow the VM access to the device. ### How can I verify that passkey cross-device authentication succeeded in my Parallels environment? After completing the passkey ceremony, check that the authenticatorAttachment value in the assertion response is set to 'cross-platform'. You can inspect this using the Passkeys Debugger at passkeys-debugger.io, which shows the full parsed assertion response. ### Can I use Parallels to test passkey flows on Windows 10? No. Parallels only supports Windows 11 on Macs with Apple Silicon (M1/M2) and there are no ARM builds of Windows 10. Reliable Windows 10 passkey CDA testing requires a real physical Windows 10 device.