Secure DIY Garage Door Opener
QCPete 
Introduction
If you'd like to increase the security of your garage door, or you are just interested in learning more about cryptography, then read on! At its core, this project is simply about a secure wireless button. This could be used to trigger any number of things, so we hope it can inspire message security on many other future projects.
I was surprised to learn that even if your garage door is fairly new, then you may still be vulnerable to man-in-the-middle or roll-jam attacks. With this tutorial, you can achieve an extremely high level of security utilizing ECC signatures and the SparkFun Cryptographic Co-processor.
If you'd like to read more about garage doors, here are two great articles about hacking and history.
During my research for this project, I also came across an interesting story about garage doors in San Francisco. In 2004, military radio signals were jamming garage door openers. It seems that most garage door openers at the time were operating on the same frequency as a new military communications system (390 MHz). For more details, check out this CBS News article. After learning this, I was glad to know that my new setup is operating on 915MHz, and so it shouldn't be effected.
Most communication channels are exposed to the world. Whether it's a hard wired connection or a wireless signal flying through the air, anyone can listen in and try to intercept, record, and/or impersonate your signal. So how do we protect ourselves against these malicious attacks? Surprisingly, you can make a very robust solution with a couple of Pro RFs and our Cryptographic Co-processors.
Suggested Reading
If you aren’t familiar with the following concepts, we recommend you read over these tutorials before continuing.