Re: Automated front door lock?

[Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Wed, 03 Aug 2005 17:28:52 GMT, nobody@xxxxxxxxxxxx (Dave Houston) wrote
in message  <42f0fb64.10964374@xxxxxxxxxxxxx>:

>andrew@xxxxxxxxxxxxxxxxxxxx (Andrew Gabriel) wrote:
>
>>In article <Xns96A58FBCD269DKeithBC4ReaderTokenI@xxxxxxxxxxxxxx>,
>>	Keith <nospam@xxxxxxxxxx> writes:
>>> Newbie here-
>>>
>>> I need to replace my front door lock/deadbolt combo, and was thinking it
>>> would be nice to put in something with a keypad where I could program
>>> several codes with different expirations (for repairmen, meter readers,
>>> etc.)
>>
>>I've thought about this for a while.
>>One significant problem you might have is satisfying your
>>insurance company that whatever scheme you have come up with
>>is actually secure. There are two sides to this. The first is
>>the physical door locking mechanism -- those which come anywhere
>>near as robust as a standard door lock/bolt are horrendously


If you control the _door strike_ rather than the _lock_  then:

1) cost for a physically robust door strike is in fact low  (~$30 ) not
"horrendously expensive"

Froogle "electric door strike"
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7503280119&category=63893


2) the part that uses electricity is on the stationary frame rather than the
moving door so the device does not need to be entirely wireless,

3) this is a standard commercial method,

4) there are a wide variety of industry-standard ( " Weigand" -compatible)
devices (keypad, key fobs (I-button, IR, RF) , swipe/credit cards, IR,
fingerprint, RFID, iris recognition etc)

5) you can change, update, use multiple key/code/entrance devices using the
same lock/doorstrike/HA control system

6) there are affordable programmable systems that are themselves HA control
systems or interface with them --for example, two distinctly different Elk
systems have already been mentioned in this thread and neither require a
computer to be in operation 24x7.

7) With a HA system (or specialized system) you can open the door remotely
or on a schedule, or response to other sensors,

8) Door strikes can be trivially interfaced to security systems  If you are
considering, or have a security system the stand-alone dead bolt systems are
a waste of money that interface poorly if at all with a HA and Security
systems (in my opinion).

9) the keystroke is completely inconspicuous, whereas the dead-bolt options
involve (in my case) removing neat old/antique hardware and replacing it
with some tacky new stuff with a different footprint on the wooden door.


>The second is the security of the software and
>>electronics side of things. If a burglar enters your house
>>through the door, I could imagine severe problems getting any
>>insurance company to pay out.

"Imagine"?  How many keypads/card-swipe/button-based entry device do you see
in a single day? Do any/all have the problems you are concerned with?

>I agree with Andrew (except for the cost - the IR dead bolts are relatively
>inexpensive and reasonably robust). Anything you find that is this
>programmable is far too complex and entails security problems of its own.

"Far too complex?" Too complex for whom, what, why? What does this mean? If
you already have a conventional security system, or (eg) an Elk system of
either style you can ad and I-button and door strike for about $75. At least
with my Savoy CyberHouse implementation of Elk's hardware, I can have two
different devices (eg, I-button + RFID or Keypad) I "imagine" that an Adicon
Ocelot could be programmed to do this (but don't know).

Elk also sells a complete turnkey system with ten, pre-programmed 48-digit
I-buttons to do this (less door strike itself).

Here it is: http://www.elkproducts.com/products/elk-mk420.htm
Available mail order for about $175
(but I'd suggest the newer ELK M1 system or a conventional security system)


>Go to www.SmartHome.com and search on "deadbolt" for alternatives. There
>are automated deadbolts that are quite secure although they do not have the
>easy reprogramming and reporting desired by the OP.

Right. Google "weigand" "electric strike plate, (not "deadbolt") and you
will get to many _responsive_ solutions.

>Anything using RF (including RFID) and not using rolling codes is suspect.
>It's too easy to capture and play back.

The technology is constantly evolving and there are many choices. Ny
choosing an industry-standard Weigand interface, your system can evolve
without defacing the door itself.

>The IR operated deadbolts use very short range IR which is difficult to
>intercept.

And don't satisfy the original posters needs because they don't interface
with HA systems or conventional security systems (last I knew).

... Marc
Marc_F_Hult