Crypto Acoustic Credential

[Chris Weiss]

so today's woot has a door lock system, but the interesting part is the audio unlock system.  it appears to be this http://www.google.com/patents/US20120172018

so basically you register a users phone number, and when they get to your house they call in, the system recognizes their caller ID (and maybe enters a PIN?  unclear) and the system generates an audio tone that the wall mounted reader can validate and use to unlock the door.

thought it was clever, there's certainly a lot of security concerns with it but using techniques similar to rolling codes you can mitigate most.  their system can also alert you anytime someone unlocks your door.