D.I.Y. Home Security

theodp writes "The NYTimes reports that pre-wired home security installations by alarm companies are on the way out. Thanks to wireless window and door sensors and motion detectors, installing and maintaining one's own security system is becoming a do-it-yourself project, with kits available from companies like InGrid and LaserShield. Time to start cranking out some new iPhone and Android apps, kids?"

Comments

Re:Wireless = less secure

[GrahamCox]

Wireless = a burglar could disable them remotely?
Either by jamming or by spoofing.
Or trigger them often enough remotely so that they eventually get disabled ;).?br>
I used to design radio-based alarm systems in the 1980s. These were the first things we'd make sure couldn't easily happen. In those days we only had one narrow-band channel to work with (allowed by law) so anti-jamming was basically a case of a loss of signal from the sensors and/or a blocking signal present at the receiver would trigger an alarm, which meant that (3) was a definite possibility. The 'loss of signal' detection implies that the sensors transmit continuously - they don't, but they do send a brief 'check-in' at periodic intervals. The check-in period was a pseudo-random sequence to prevent different sensors checking-in on top of each other (since they couldn't 'listen out') and as a result the receiver could very quickly determine whether a sensor had missed its checkin. Later spread-spectrum techniques got around most kinds of dumb jamming attempts - it would still be possible to spoof the system in theory but only using relatively sophisticated bogus transmissions. And spoofing is reasonably easy to prevent in the decode software. I assume most modern systems today will use much better techniques than we had at our disposal twenty years ago.

I'd say this though, as a former alarm engineer - if you really have something to protect, the best security is physical, not an alarm. If you can't secure your own building go to someone who can, e.g. safe deposit boxes. Alarms are pants, whether they use wireless or not.