We’ve already seen several major carmakers jump into the IoT, showcasing in-vehicle payments tech.

Most recently, Jaguar and Shell showcased fuel payments tech in the U.K.; Honda and Visa had their take on in-car payments at CES 2017, while GM teamed up with MasterCard and IBM last year to enable Masterpass digital wallet on its OnStarGo app.

So far, most of those collaborations have been centered around good old mobile wallets and bank accounts; or, in other words, traditional currencies. But this may change soon.

The telecom conglomerate AT&T filed a new patent application with the U.S. Patent and Trademark Office, exploring the potential use of digital currencies– such as BlackCoin, Dash, Dogecoin, DigitalNote, Ether, and Ripple XRP, among others– for in-car purchases.

The patent application, “Vehicle System With Vehicle Report Generation and Methods For Use Therewith” filed last week, describes the “vehicle system,” including a “processor, configured to communicate the digital currency record for use in conjunction with a purchase of goods or services by the user, wherein the digital currency value is credited to a purchase price of the goods or services.” It seems that the system would work both via a mobile app, and a car’s dashboard.

From the USPTO document:

The vehicle system 325 can directly communicate the digital currency record via communications interface 310 to a point of sale terminal of a merchant 350, such as during a drive-in service. In this fashion, a user on a road trip can spend digital currency generated on the trip at a gas station, fast food restaurant or cafe with a drive-up window. In other examples, the vehicle system 325 can communicate the digital currency record via the communication interface 310 to a payment card 340 or mobile communication device 330 associated with the user–either directly, or indirectly via a network such as communications network 125. In this fashion, the payment card 340 such as a credit card or a payment application (“app”) executed by the mobile communication device 330 can be used at a point of sale terminal at a merchant, as a credit for the purchase of goods or services. In yet another example, the digital currency record is communicated via the communications interface 310 and a network such as communications network 125, to a server that holds an account associated with user. In particular, the digital currency value is redeemed by crediting an account of the user, such as a bank account, credit card account, or other payment of service account of the users that hold a monetary value.

The patent goes on describing the various applications of the potential technology, including “generating a vehicle report based on the vehicle data; generating in accordance with a cryptocurrency protocol, a digital currency record that is unique to the vehicle report, wherein the digital currency record indicates a digital currency value associated with the vehicle report; and storing the digital currency record in the memory.”

It’s unclear when (or if) this technology will come to life, and whether more merchants will be open to accepting crypto payments by then.

The transaction volumes for bitcoin– possibly the most popular digital currency out there — have been mostly on the rise since 2009. Here’s a useful tool to help you keep track.