Consumers now have their choice of several smartphone-controlled door locks, which allow users to grant access to select people, and that automatically cause the door to unlock when a user approaches. San Francisco-based startup Mesh Motion has taken those same ideas, and applied them to a bicycle security device known as the BitLock.

Invented by mechanical and computer engineer Mehrdad Majzoobi, the lock is made from heat-treated steel, and has a Kryptonite-like U-lock form. Inside of it, however, is a microprocessor and an electronic locking mechanism. When a paired iOS or Android phone gets within three feet (0.9 m) of the lock, the phone's Bluetooth signal causes the lock to disengage – assuming the phone is running the accompanying BitLock app. The user then simply has to press a button on the lock to release its shackle.

Likewise, when the lock is placed on the bike and the user walks away (with their phone), the lock automatically engages. That said, it's also possible to "arm and disarm" the lock manually via controls on the phone's screen.

Additionally, when the lock is engaged, the app uses the phone's GPS to make a note of the parked bike's location on a city map. This not only allows the primary user to find their way back to it later, but it also allows trusted people in the user's "permission group" to find the bike for themselves, if they wish to borrow it. As long as the user grants them permission and they're running the app too, they can use their own phone to lock and unlock the bike.

Multiple groups can be created, to which people can be added or removed at any time.

The BitLock is waterproof, and is powered by a single non-rechargeable lithium-thionyl chloride battery. That battery should reportedly be good for about 10,000 lock/unlocks, and a notification appears on the user's phone when it needs to be replaced.

As with any other smartphone-controlled device, the question of "What happens if your phone's battery is dead?" does come to mind. Well, since your user data is stored in the cloud, you'd have to use someone else's Bitlock-app-running phone to access it. That does sound like a bit of a hassle, but then again, it's also possible to lose the key for a traditional U-lock.

Majzoobi and his team are currently raising production funds for the BitLock on Kickstarter. A pledge of US$79 will get you one, when and if they're ready to go – the estimated retail price is $140.

More information is available in the pitch video below.

Sources: BitLock, Kickstarter

UPDATE (Oct.17/13): Majzoobi has just informed us that he plans on adding a feature in which a user-specific binary unlocking code can be entered using two buttons on the lock, in case the user's phone battery dies.