Ultra Wideband at Vouch.io

I’m a product engineer at Vouch.io where we are building digital access product for people and cars, and I’d like to share a bit about our use of Ultra Wideband, giving a bit of an “inside view” of this remarkable new technology and what it means for us going forward.

Our product, Vouch Key Automotive, allows for digital access to cars from a smartphone or wearable device. One of our goals is to abstract the need for the phone to interact with the vehicle, much like you do today with proximity-based keyfobs. Security is a considerable concern with current RF and BLE based approaches, and we aim to solve that using Ultra Wideband.

First, to set the stage, a bit about our foundational product, Vouch Identity: At its core, Vouch Identity removes the need for passwords or shared secrets and instead creates cryptographic proofs that link a person to a device and then ultimately biometrics for authentication. As you might expect, we use Vouch Identity to protect and access our own internal and SaaS-based systems. As a developer, for example, I use it to access GitHub and AWS Console.

One thing you appreciate when using Vouch Identity on a day-to-day basis is just how much the integrated biometrics eliminates friction. This means no more typing passwords, or even messing with a password manager. For example, when logging into GitHub, I receive a notification on my iPhone, perform a quick Face ID check, and I’m in.

Building on that capability, we have our Vouch Key product, which has brought the benefits of the underlying Vouch Identity product to the physical world of cars, homes, hotels, etc. and providing ultra-secure ways to allow certain identities to interact with doors, locks and other devices. We also use Vouch Key in our day-to-day lives: I use Vouch Key to unlock and lock my Prius whenever I’m out and about.

With Vouch Key, the elimination of friction also plays a large, if not more prominent role…

This is where being a product engineer at Vouch, dogfooding our products is fun: Using your mobile phone to unlock your car is novel. We’ve also managed to eliminate BLE latency so that unlocking twice as fast as a physical key fob. This is very cool from an engineering standpoint.

But, pulling out your phone just to unlock your car can be a drag. We’ve improved this by extending Vouch Key to the Apple Watch, making unlocking as simple as raising your arm and tapping on the app.

That’s better, but what you really want is for the car to unlock as you approach it automatically. A digital key should not simply replace your physical key, car key fob, but improve upon it.

This is where Ultra Wideband comes in. It is perfect for securely detecting proximity. While you can use BLE signal strength (RSSI) to detect rough proximity to the vehicle, we’ve found that it leads to an inconsistent and unreliable user experience.

We’ve taken Ultra Wideband hardware and incorporated it into the in-car units used with Vouch Key. Here is such a unit below… you can’t see the Ultra Wideband chipset and antenna — trust me, its inside the unit!

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Ultra Wideband distance measurement works by measuring the time-of-flight of radio signal pulses from one device to another, using extremely high frequency gigahertz counters for signal timestamping and doing some fairly straightforward math involving the speed of light. When properly calibrated this results in centimeter-level accuracy!

Here is an engineering test of me using Ultra Wideband to unlock and lock my Prius at specific programmed distances away from the vehicle.

Not only is this highly accurate, just as important is that it is rock-solid in its reliability. In my opinion, this is a profoundly transformative technology that dovetails nicely into the Vouch Key product, completely eliminating friction.

With this, we can deduce not only simple notions of proximity, but we can tell which side of the car you are on (or even which door you are approaching). This becomes important for the overall user experience — a digital keys need to readily reliably detect which side of a door you are on, or which particular door of a car you are approaching.

This technology will also allow us to detect and prioritize a driver over a passenger when unlocking a door, or pairing the phone closest to the driver’s seat for BT audio, use Ultra Wideband keyfobs for valets, or service appointments etc.

I’m excited with how we are able to bring Ultra Wideband to bear on improving the experience of using Vouch Key and I’m looking forward to leveraging it in other ways as we enhance the Vouch product suite when interacting in the physical world!

Written by

Vouch.io and ClojureScript maintainer

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