That four digit garage keypad code is a joke. It's as good as a two-character password, says an article on wired.com. Even if you don't know the code to work off of if it's been changed, it can be cracked in seconds, says security researcher Samy Kamkar in the wired.com article.
Kamkar refers to a tool, OpenSesame, which was created from a child's toy called the IM-ME. The pocket-size device works only on "fixed code" garages, not ones with "rolling codes," and tries every possible number combination.
The OpenSesame can open garage doors from the street. If it tries every one of the over 4,000 possible combinations that it's capable of feeling out, it would take 29 minutes. But Kamkar took out some bugs, reducing the total time to eight seconds. This works for one frequency. To go through all four frequencies that garage door openers operate on, it would take under one minute.
If your garage has a fixed code, you may want to change it to the more secure rolling code. But don't be surprised if Kamkar comes up with a way to hack rolling code receivers.Kamkar gained notoriety when he infested MySpace in 2007 with a worm, quickly giving him over a million friends. You can say this guy is pretty smart.
And if he pulls off the rolling code hacking tool, then how do we secure our garages? Maybe someone will come up with a way to rig the receiver so that if it's hacked, the sound of a ferociously barking dog will result, making the hacker/burglar think that inside the garage awaits Bruno or Duke, ready to bite a big chunk out of anyone who intrudes upon the garage.