‘Knock’ Unlocks your Mac with your iPhone: Does It Work? [Review]

Today a new iOS app launched called Knock which can unlock your Mac by ‘knocking’ your iPhone screen like you’d knock on a door, making many tech headlines. The app uses Bluetooth Low Energy 4.0 to create a secure connection between your iPhone and Mac.

But does Knock actually work as shown in the video below?

We just purchased the app and set it up on our 2012 MacBook Air and iPhone 5s. We’re happy to report—it works exactly as described.

Faster and safer than typing a password, for iOS and Mac.

You keep your iPhone with you all the time. Now you can use it as a password. You never have to open the app— just knock on your phone twice, even when it’s in your pocket, and you’re in.

Using Knock won’t drain your iPhone’s battery, even if you use it all day every day. Knock securely communicates with your Mac using Bluetooth Low Energy, a new technology that draws very little power.

Knock works with any Mac that supports Bluetooth 4.0.

Below are images of the Mac and iPhone setup, which was pretty easy:

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Photo 1

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Photo 1

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You do need to give your iPhone a firm couple knocks for it to unlock your Mac, which works pretty instantly. This we assume prevents ‘accidental’ unlocks.

You can also unlock your Mac by just giving your iPhone a couple firm ‘shakes’, like you do with the app Bu.mp or even tapping your iPhone on its side on a surface. That also worked for us and would probably save you from having to ‘knock’ your iPhone multiple times per day if that scares you.

The app requires an iPhone 4S, iPhone 5, iPhone 5c or iPhone 5s and the following newer Macs shown below:

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If someone steals your iPhone, you can still login to your Mac with your password, then disable the Knock app. The app uses Bluetooth’s built-in encryption and Knock’s proprietary 1024-bit RSA encryption to create a secure connection between your iPhone and Mac.

Knock was created by William Henderson and Jon Schlossberg. Henderson created a secure mobile payments platform at Square and previously worked on OS X at Apple. Schlossberg previously directed the design at ecommerce system at online clothing retailer Bonobos.

So, should you buy Knock? That’s up to you and how frequently you’re unlocking your Mac, but in our quick tests, the app works exactly as described.

Click here to download Knock for $3.99 in the App Store. The Mac app client is a free download, available here.