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Bypassing Security Things

— Posted by Darkie on 4:17 pm on Mar. 7, 2002

I have little knowlage when it comes to security electronics. Someone please share your knowlage.

Lets say i want to get into a room and i am lucky enough to have the keys or can pick the lock. The door comes in from the outside. The security measures are…
1. On the top of the door there are one of those things..heh… where one piece is mounted mounted on the door and one on the door frame and if they are seperated the alarm goes off.
2. There is a motion sensor in the corner. It’s a white half cylindar with a opaque plastic screen where i guess the sensor is.
3.Ultra sonic detector. I recently heard about these and they were recently installed. They are 3inX1.5inX.5 in dimensions. They are white except two small holes.I think he signal is emitted from one and recieved by the other. If the incoming signal is changed after it is turned on then the alarm goes off.

I have access to all of them so if anyones knows how to disable them i would like to know.

— Posted by Thanatos on 6:17 pm on Mar. 7, 2002

i can help with the first one
take the two halfs of the sensor togeather and rip them both off the wall at the same time so it doesent go off dont open them up cause they are ‘tamper proof’ (o off if damaged)
i’m not sure about the other  two

— Posted by Hergor on 6:25 pm on Mar. 7, 2002

are you able to get somewhere near those other two when the alarm is not yet armed?

(Edited by Hergor at 6:25 pm on Mar. 7, 2002)

— Posted by drybilgeltd on 7:08 pm on Mar. 7, 2002

The do- hickys on the door and door frame is not very difficult. The thing on the door is a magnet, the gizmo on the door frame is a magnetic sensitive switch, most of them make contact when the door is closed.   Some how get to the wires and short them together or undo the magnet from the door and while keeping it against the switch,  tape it to the switch on the door frame.  If you go to Radio Shack they have these tiny super duper magnets, stick one one the switch when the room is normaly open and no one is looking.  

 The ultrasonic sensor I had to scratch my head a little. I have a little experience on them but not much. My job at the time was to fix brohen ones. Get some electronic test equipment. Items need (1) ultrasonic microphone, (1) frequency counter, (1) preamplifier suitable for 20khz to 100khz. Using these items you can find the frequency this thing is working at.  After that is found, by using an audio generater set for the same frequency and a small amplifier  ( get an LM458 IC from Radio Shack and some other parts )  connected to a small ultrasonic transducer and some wire. Somehow slowly get the transducer near and aimed at the ultrasonic sensor thing and very slowly turn up the volume on the audio amplifier.  The idea is to blind the sensor to its own signal frequency so it will not notice the sounds bouncing around the room.  If I get another one of these things to fix I will try it out.

 The motion sensor detects your body tempature as being different from the room surroundings.  The idea is to make you look like the tempature of the room or the other way around.  See if you can get something that looks like the cover on the motion sensor.  Cover the inside of it with some thing that light does not go through ( maybe aluminum foil ) when no one is looking put it on the motion sensor.  That might be easier than trying to raise the room to 98.6 degrees so that you and the room are the same.  Maybe you can disable the burglar alarm.

— Posted by Darkie on 4:45 pm on Mar. 8, 2002

I know where the keypads are but they would be too hard to get to plus i have no idea how to operate them. For the motion sensor i was figuring at the end of the day hanging a piece of paper in front of it. I wasn’t sure if this would also work for the sonic detector. That is a god idea for the door alarm. People rarely use the door so with a screw driver and some creative tapeing i should be able to dicreatly disable that.

But, might the alarm go off or refuse to arm if something is hanging in front of either the motion or sonic sensor?
The hightech answer to the sonic detector is good but i would use all that stuff maybe once.

— Posted by MachiavellianSmith on 12:32 am on Mar. 10, 2002

first of all, if i say something that contradicts something said in a previous post, then it just means that there’s more than one possibility. (or at least i think so)
1.Ultra sonic detector–chances are that they are tuned so that they only detect noise levels such as windows breaking, etc. some can be set lower so that a sneeze would set it off, but they can be set for all the time as to not interfear w/ daily use of the building.(by the way, it would really help if u told us what kind of building this was, because the ‘right’ solution will variy from a bank, to an office building to a school, to a yuppy’s house)
2. There is a motion sensor in the corner– okay, just to set the record straight, not every one of these are “mission impossible” style where u gotta up the temp to 98.6 degrees then u can walk past it. generally, the sensor will pick up ANY movement of decent size(could be as small as a baseball). however, covering the sensor is the quickest and most easy way do deal w/ it. i like the aluminum foil idea, but just paper might work too. most of ’em have a red or green light on them that turns on when they detect something. if not, u might hear a small ‘click’ sound. hell, maybe just some clear tape will block the signal.
3.On the top of the door there are one of those things..–yeah, well they’re easy and drybilgeltd knows what hes talking bout. and i do like that frequency blocking idea of his. also,
as far as the keypads, if its a house, its 50/50 that the passcode is the last 4 digits of the phone #. if its a buisness, then they could change the code every month or more.
lastly, neither the motion or sonic sensor will create the system to not arm, because its not like u cut the cord– u just changed what it is that it is reading. all its doing is relaying the wrong info.

i know im still a new member, but thats cause when i post something it usually means i know what im talking about. anyone who want to tell me how little i know can email me at kickboxer44@hotmail.com (or just questions)

— Posted by drybilgeltd on 10:59 pm on Mar. 10, 2002

The ultrasonic sensors I delt with in the past was a long time ago and they were kind of cheap. They had 2 ceramic transducers in them ( using the piezo effect ). Each transducer had the same resonant frequency. One transducer was used as a speaker in an oscillator circuit where it was the frequency determining device. The second transducer was used as a microphone. Because the transducers were a matched pair, they had the same resonant frequency. The sound from the first xducer would bounce around the room and be picked up by the secound one. Imagine you are in a room with your eyes closed but there is some light comming in the window. You can not see features but can see the presents of light. Somebody uses a mirror to shine the sun on you or walks past to block the light. In either case you can see the change. The ultra sonic waves bouncing around add and subtract and interfere with each other ( like the misterious standing waves on a transmission line ). With nothing moving in the room a fixed pattern is set up and and the second xducer gets a sample of it. When something moves in the room the pattern changes thus the sample changes. This signal from the second xducer goes to an amplifier then to a circuit that detects a change in amplitude. Up or down makes no differance. If there is a slow change the circuit will not trip ( over a period of many seconds like watching paint dry ). We are trying to shield the second transducer from the ultrasonic waves bouncing around in the room. Sounds like breaking glass etc or somebody farting are not what sets off the ultrsonic sensor. Newer types may use a pulsed technique rather than a constant tone from the first xducer. This would be the high dollar cadalac type that I have NOT worked on.

Motion sensors are sensitive to heat waves ( infrared ). A car going by has a hot engine and will turn drive way security lights on. Again the sensor has a referance that it compares against. If you are in front of one and do not move for a while the lights go off. A room will have a certain overall tempature. If no one is in the room, what movement will there be? If the sensor is seeing a cold object or a heat source and then something moves between the sensor and tempature source the sensor reacts to the change. Our body is 98.6 degrees, if the room is 98.6 degrees there will be very little change to trip the sensor. Blind the sensor and it should not set off the alarm. The purpose of the cover in my previous post is to hide the aluminum foil.

(Edited by drybilgeltd at 3:05 pm on Mar. 10, 2002)

— Posted by preditor on 1:48 pm on Mar. 12, 2002

you guys are thinking too much into it, sometimes the most complicated problems have the simplest answers. Darkie do you know if the security system is connected through tho phoneline, the cabel line, or is sent through the air? instead of disasembaling the entire set of security components, make it so they work but cant send an alrm call to the security proveder, (cut or remove wires leaveing the building)

— Posted by confuzious on 6:00 pm on Mar. 12, 2002

If there is a keypad to disable it you might be able to rig a hidden video camera to record the code. What kind of building is this anyway?

— Posted by Darkie on 9:38 pm on Mar. 12, 2002

umm…it might be a school. Either way the building/s are way to big, it would be too hard to find the center of the alarm system. It’s prolly locked in some closet anyways, hmmmm, i wonder when my lock pick kit is coming?

— Posted by Darkie on 9:51 pm on Mar. 18, 2002

Ok, the sound detectors…I think i figured out a way to semi disable them. What if i covered one in either the foam in a can stuff or made a peice or packing styro foam to fit over it? would that help?

— Posted by Darkie on 5:48 pm on Mar. 20, 2002


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