A patent filed by Ford details how it could use finger prints, retinal scans, and voice recognition to make your car keys obsolete. Sounds good. But what about security?

The patent, , outlines a system that uses a smartphone (or Personal Communication Device) to connect to a car's controller over either Bluetooth or WiFi to. At it's most basic level, it would lock and unlock the doors. But that's just the start.

Using a biometric capture device, Ford could identify the driver through different means, including a retinal scan, a fingerprint sensor, a voice recognition unit, or just a facial image that could send a signal to the vehicle controller to unlock the car.

The data would be collected and stored on the smartphone and then sent to the vehicle, and other users could be added to the car's database. You could authorize a family member to access the vehicle by granting them privileges for a certain amount of time – to grab the bag they forget out of your car – after they've used some kind of biometric data to identify themselves.

For Ford, which is pushing deeper into car-sharing, this could be a way for it to make swapping easier, nixing the reliance on a physical key to open and start the vehicle. It could also be used to restrict certain features based on the driver – say, allowing a teen to access one radio station or only drive during certain hours at certain speeds – all controlled by the vehicle's "administrator".

It might be far off for now, but Ford , and the technology is there, although there isn't much detail about it plans to keep all this information secure, which is a bit worrying.

Image: Getty