Multi-Layer Security

Bruce Schneier has an excellent essay posted on his blog. It deals with a security mechanism we are all familiar with, physical locks. It’s no secret physical locks can be bypassed via lock picks, bump keys, and random everyday objects. Few people realize though how insecure the lock on their front door is. On top of that most physical locks require a key, which many people find inconvenient.

Lock companies have been trying to solve both of these problems through more secure locking mechanisms and keyless entry methods. Of course as with any security related items these new methods are introducing new ways of exploiting physical locks. I don’t think there will ever be a secure lock, there will always be methods of bypass. But locks are important because they add another layer of security.

Having one layer of security is never a good idea since an exploit in that layer will leave everything behind it vulnerable. Case in point if somebody picks your lock they are through the front door. If you have no other security layer everything in your home is fair game. Now let’s add a large guard dog to the mix. Once the criminal bypasses the lock they will have to deal with the dog. This can be accomplished by simply killing the thing but if you are in the house and you hear the dog bark that gives you a few seconds to prepare. That would imply a third layer, you. Hopefully that third layer has a gun to add another layer between you and the criminal.

Security can only be properly done in layers, and each layer should complement another. No layer should be exploitable via another layer. In other words using our example bypassing the front door lock won’t affect the dog. Bypassing the dog won’t affect you and your gun. Meanwhile as mentioned in the link Schlage are introducing Internet enabled locks. This ties your physical security to the security of your computer. Should somebody exploit your security layers on your computer they also exploit one layer of your physical security. This should never be the case.

When planning a home defense strategy make sure you have multiple layers. Even seemingly unimportant things will require time on the criminal’s behalf. The more time the criminal wastes the more time you have to properly respond and prepare. Sure having two locks on your font door (always ensure one is a good dead bolt) may seem like a meaningless idea since it only prolongs the criminal’s entry it does prolong it. Those few additional seconds could buy you enough time to round your family up in a secure room with only one entrance that can be covered with a shotgun.