Open Radar

 
The new Touch ID system in the iPhoen 5s hardware is a breakthrough on a mobile device, but is severely limited as there is no announced API to allow 3rd party developers the ability to integrate this sensor into applications. 

I am currently developing an application that uses a pin number to give users access to secure data. With a fingerprint reader API, I could automatically authenticate the user with my application and log the user in. The fingerprint reader technology has numerous uses: keep kids from accessing certain applications, automatically switch users when loading an application, etc. If only there was an API.

Such an API could be integrated into Keychain Access or another security API. To keep the user's fingerprint secure, you could return a hash of the fingerprint instead of the actual fingerprint. This would be just enough information so that the user's identity could be verified, without risking rogue applications from taking a user's fingerprint and using it in an unauthorized way. 

The user could also enable/disable this feature through the Privacy section in Settings, no different than access to Twitter and Facebook identities.