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[inode]

Hi all,

I'm planning to get an X10 alarm system but I can't find detailled informations about security. Here my questions:

- the X10 security extension has the ability to identify jamming signal? For example using a DS12A the system will identify if the sensor is not reachable because there is something that jam the signal of the sensor?
- the X10 security key chain (like the KR21) do a challenge response with the system or just send an ID? It's possible that someone "sniff" my KR21 and it's able to replicate my keychain?

Best regards,

inode

[Brian H]

The security sensors send a heart beat message about every hour. The console if it misses four of them will flag a zone error. I don't think the console can detect a jamming signal.

The KR21 sends it commands and has no way to receive anything back from the console as a challenge.

[inode]

The KR21 sends it commands and has no way to receive anything back from the console as a challenge.

So if someone can "sniff" the data it's able to replicate the command and disable the alarm...

It's that correct?

inode

[dave w]

The KR21 sends it commands and has no way to receive anything back from the console as a challenge.

So if someone can "sniff" the data it's able to replicate the command and disable the alarm...
It's that correct?

Not exactly. If the console does not receive a "heartbeat" for four hours, it only indicates on the display that there is a problem on that zone. The alarm is not triggered. If the security sensor is triggered (break-in) it sends a signal to the console which triggers the alarm. There would be no point in replicating that. However that RF signal can be jammed by an external transmitter transmitting on the same frequency.

If you have burglars in your area sophisticated enough to jam RF based security systems, or you are concerned that that may happen, then you don't want X10, or any "wireless" security system.

[dhouston]

If you have burglars in your area sophisticated enough to jam RF based security systems, or you are concerned that that may happen, then you don't want X10, or any "wireless" security system.

Agreed. It's important to understand this issue although jamming is not the major risk. A lot of security and home automation manufacturers and vendors trumpet the fact that they use encrypted RF signals. Encrypted signals are just as easily sniffed and played back with the same result as non-encrypted signals. Rolling codes are fairly secure and immune from sniffing (although some university students have broken KeeLoq).

I would not trust either an alarm system or a garage door opener unless they use rolling codes.

[dave w]

If you have burglars in your area sophisticated enough to jam RF based security systems, or you are concerned that that may happen, then you don't want X10, or any "wireless" security system.

$0.02
My statement might be a little too broad in commendation. I think a system using "spread spectrum" or CDMA RF transmission might be very difficult to jam. But again, if there is "worry" about jamming then a wired system is the only "peace of mind" solution.
Also the axiom of :"You get what you pay for" is very true in security systems.