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Windows 10 will soon let you unlock your PC with approved 'companion devices'

Microsoft recently published their roadmap for Windows 10 and Mobile one of the interesting features on it was unlocking a Windows 10 PC with a companion device. Now, the company has gone ahead and detailed how that Companion Device Framework (CDF) will work including what options developers would need to take to enable the feature.

The details including the model of the framework, restrictions, and requirements are all revealed in a new developer article published today by Microsoft titled 'Windows Unlock and companion devices' (opens in new tab).

The idea behind the Companion Device Framework is simple: you want to utilize the Windows Hello and Passport security features, but the hardware does not have a fingerprint reader or biometric camera. Using an external device can complete that process, so long as it is secure and uses the CDF. That ability is good for two reasons (1) old hardware that does not have builtin biometric features and (2) low-cost hardware where consumers may want to add the security feature later.

Microsoft details some other usage scenarios:

  • Attach their companion device to PC via USB, touch the button on the companion device, and automatically unlock their PC.
  • Carry a phone in their pocket that is already paired with PC over Bluetooth. Upon hitting the spacebar on their PC, their phone receives a notification. Approve it and the PC simply unlocks.
  • Tap their companion device to an NFC reader to quickly unlock their PC.
  • Wear a fitness band that has already authenticated the wearer. Upon approaching PC, and by performing a special gesture (like clapping), the PC unlocks.

The first example sounds an awful lot like a YubiKey (opens in new tab), which acts as a 2-pass-authentication for things like LastPass. The second example is something that Windows 10 Mobile users can expect likely this year with the Redstone update, and it should prove to be very convenient. Likewise, the fourth option is aimed at Microsoft Band users and should provide yet another way to get into your computer without typing a password.

Not all apps can just jump on board with Microsoft's CDF as developers will need to be "specifically provisioned by Microsoft and list the restricted secondaryAuthenticatorFactor capability in its manifest." That translates to applying for approval as the system deals with security, logging in and could jeopardize user privacy.

Interestingly, Samsung has already done this companion unlocking, and it exists today. The new Galaxy TabPro S with Windows 10 can be unlocked via the fingerprint reader on the Galaxy S7 and S7 Edge using an app called Samsung Flow. We'll have more on how that system works in a forthcoming article shortly.

Daniel Rubino is the Executive Editor of Windows Central, head reviewer, podcast co-host, and analyst. He has been covering Microsoft here since 2007, back when this site was called WMExperts (and later Windows Phone Central). His interests include Windows, Microsoft Surface, laptops, next-gen computing, and arguing with people on the internet.

58 Comments
  • So if i plug my Lumia 640 with windows 10 to my low end windows 10 PC and tap a notification itll unlock? Neat :) Me likey
  • Pretty cool, yo'
  • Clapping while wearing my Band to unlock would be so cool :D
  • Quick, someone create the Clapper App, it's Icon would be a lampshade that obviously light up for On and goes dim for Off...
  • Gesture unlock!! Using accelometer and whatever sensors there are available to "draw" a pattern in the air instead of pin/password Posted from WC 920, 1520, 920, 635, 640 or 950XL
  • That'd be really cool
  • I love Windows articles because a lot of them always feature the word "Soon". I laughed when I saw that.
  • It's only funny because Microsoft is so transparent with what they are doing and what they are building out. It is exactly what people wanted and now the company is made fun of for it. Apple has a roadmap too they just keep it internal. If they made it public, we could easily point to a couple dozen features, fixes and new hardware "coming soon" as well. This is the flipside of knowing what Microsoft is doing and where they are going. No need to point it out each and every time.
  • It's just a joke jeez
  • and now everyone hates you @eddp77 Posted via Universal Windows App on W10
  • We've hated him since long. Not now :P Posted via the Windows Central App for Android
  • Couldn't give a fù©k lol
  • It's not the fact that they disclose features before they ship them. But the fact that they present them as something that will be available soon and is usually available "late" or not available at all that is the source of many jokes.
  • What features have they failed to deliver? They announced like half a dozen or more features at Build and the next week the Fast Ring Insider build had the majority of them. Anniversary Update is set to ship later this summer (likely July) and they seem well on track for that release.
  • Windows 10 Mobile will be available for all WP 8.1 phones soon. ------------
    iPhone first, iCloud first.
  • Looks like you badly need a new dead horse Posted from WC 920, 1520, 920, 635, 640 or 950XL
  • Looks like you badly need a new dead horse Posted from WC 920, 1520, 920, 635, 640 or 950XL
  • The ability to text from my PC instead of having to reach for my phone. The ability for a smartwatch to receive messages and phone call notifications. Only the Band does this. It would be nice to have a watch style device as an option. Some kind of mobile payment. ​Those are the 3 most convenience functions that are available on the other platform that they been slow at releasing.
  • "The ability to text from my PC instead of having to reach for my phone."
    Been there since late last year. You use Cortana to do it.
    "The ability for a smartwatch to receive messages and phone call notifications. Only the Band does this. "
    False, Garmin devices do this as well as Vector smartwatches. I have written on both extensively here.
    "Some kind of mobile payment. "
    Fair enough on that one, but the other two are there and are constantly improving. We know the Anniversary Update does even more for phone/PC tie-in for messaging, etc. Considering Windows 10 for PC is 9 months old and comparing the amount of updates they have delivered (with new features) we are being slightly impatient.
  • Thanks for the Garmin VivoactiveHR tip. It will be available for in the second quarter. At least it looks like it has the messagine working unlike the Fitbit Blaze. I want the heartrate monitor for working out. The TYLT VU 2.0 should be about to be released shortly as well. Things are looking better.
  • Is waiting for two years for Cortana in Poland long enough to be at least slightly impatient?
  • What exactly do you mean by "some sort of mobile payment"? Posted from WC 920, 1520, 920, 635, 640 or 950XL
  • Cause, there's been an NFC payment option for both w8.1 and w10 quite a while now Posted from WC 920, 1520, 920, 635, 640 or 950XL
  • I'd love to know how you're using it. I have a 950XL and an NFC sim.
  • I can think about the "New Lock Screen" for WP8.1 that they tried with Rudy and them forgot about it... But the real problem is not the "late" avaiability, but that the others OSs get it first.
  • @Daniel Just wanted to thank you for really being active in trying to get people to change there tune, while Poopyfinger (feel weird typing that) is not one of the major offenders, its nice to have the person who's name is on the site help try and bring some logic to the comments. AT this point, for some, Microsoft is damned if the do, and damned if the don't. Your analogy of Apple's internal doc is perfect... :) THX!
  • Thanks, I mean, I get the joke too after all, we kind of started it here. However, I think at this time what Microsoft is doing is unprecedented (compiling 300 OSs builds/SKU per release every week) along with feedback, telemetry, commenting and more. At some point, we need to just roll with these updates and enjoy what is coming soon. Otherwise, Microsoft might as well close the doors and keep us in the dark or be a lot less forthcoming with what is coming next.
  • Sir,I think you are a Microsoft fan boy like me Posted from L540
  • I want a feature similar to Android where once entered the pin, the phone stays unlocked while it's near a Bluetooth enabled trusted device, like a PC, car or headset
  • Very good idea Marcos
  • YES! THIS!!!
  • Isn't it already available on Windows 10 Mobile devices? Posted via Universal Windows App on W10
  • Just wait, it needs to be a feature on more android phones and then it will get the "Coming Soon™" treatment.
  • I'm pretty sure there's a feature called "Smart Lock" in Android 5.0+ which has the features you mention. It also has the ability to be unlocked in a certain place, like your home.
  • Yep Posted via the Windows Central App for Android
  • Hope that companion app will be available for older Lumia phones.
  • Probably will be as long as it runs W10 mobile. Microsoft has said they stopped developing new features for WP8.1.
  • Yes! Soon!!!!!! Winning :S
  • I like all these of features, but I just hope you're able to mix and match these as two (or more) factor authentication methods. Seriously, how insecure is it to let your phone automatically unlock your PC with no other form of authentication to go with it? Now if I can use my face (Windows Hello) & detect my phone to authenticate. Or use a pin + get an approval notification on my phone, then this is great.
  • But in the article it is a two step process. Posted from Windows Central for Windows 10 mobile
  • Two "steps" doesn't necessarily mean two means of authentication. Anyone can pick your "companion device", walk over to your PC and tap the space bar to get logged on.
  • Nice
  • A pity it requires Bluetooth pairing between the PC and the phone rather than also allowing the system to work via some other connected Bluetooth device such as my DT904 Charging plate.
  • Or just internet connected PC/mobile device. Like, when I get home, as soon as my phone connects to my home WiFi it would prompt me to use Windows Hello (in this case iris scanner on my 950XL) to unlock my PC. And/or quick action and/or tile to "sign in on my (other) device" that would also utilize Windows Hello but even when not on same WiFi as long as both devices are connected to internet. Also a sign-in option when logging in to my desktop to use a "companion device" to verify my login. Posted from WC 920, 1520, 920, 635, 640 or 950XL
  • Hopefully it can work with the Fitbit Charge HR and/or Blaze. Connect via bluetooth, do a gesture, and it unlocks. I doubt it will happen since Fitbit is more workout focused than smartwatch focused, but it would be nice.
  • the developer would need to implement that feature. Posted via Universal Windows App on W10
  • My Band 1 is old and has been superseded. I know that. But I would love for them to bring this to Band 1 owners. Slim chance, but it'd be brilliant.
  • "Carry a phone in their pocket that is already paired with PC over Bluetooth. Upon hitting the spacebar on their PC, their phone receives a notification. Approve it and the PC simply unlocks." I really hope this will work with Android phones as well using a special app, I'd really dig this.
  • Samsung already did it. I'll talk more about it today.
  • If you have to interact with your PC in any way physically why not just go heard and unlock it? Makes more sense to have something completely PC-free with prior authentication, the latter two options seem a better fit for this functionality.
  • Because you can give others guest access to your PC without you being there. Likewise, you get notified if someone accesses your PC.
  • Maybe I missed something, but I didn't read aything that indicates that it can be done remotely. 
  • Even better would be: Press a hardware button on your phone while nearby to approve the notification and unlock your computer, instead of having to wake the phone, unlock it, open notifications, tap on it.
  • Cool cool cool
  • So when are we getting a proper consumer-market ready Windows Hello camera for the PC?  It's been like a billion years already....
  • For the second scenario (phone in pocket) how it saves any time to pull my phone out, wake it, and tap a notifcation instead of just typing my password.
  • Is it something like Trusted Devices on Samsung? I always get the notification when I connect my Bluetooth headphone to my Note 5 to as trusted device which will keep my phone unlocked. I haven't set it up since Bluetooth headphone without any security feature can keep my phone unlocked is a bit of risk.  Here its seems other way around that the device with biometric security unlocking the other device...  Just trying to get my head around it...and thinking of practical uses of it.
  • I tried to find something like this for Android phones and found something: KeyLock. Using this software, you can use any Android device to lock/unlock your PC.