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OpenSesame – A device that can open fixed-code garage doors in seconds

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Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#81

Post by tptacek »

mrb wrote: post #66
Cymen wrote: post #50

Earlier quoted context omitted.

Somewhat of a tangent, but I am concerned about the MITM attack on car locks [1]. This kind of attack is being used in my neighborhood in Oakland, California and no doubt other places. I read the reports of "someone is breaking into my car but no windows/locks are broken". Then a couple other people on NextDoor chime in with the same thing and one person reports a woman who is walking around the neighborhood and appe…

Yeah, a car's passive entry system can definitely be exploited by relay attacks. Here is an academic group who demonstrated it: https://eprint.iacr.org/2010/332.pdf The most obvious way to mitigate is to have the car require the key to send the first bit of the response at most N nanoseconds after the last bit of the challenge is sent over the air. Because of the speed of light this assures the key is within a certai…

Neat; Aurelien is my co-chair for USENIX WOOT this year. Now that I know his name, I keep noticing amazing things he's worked on.

Thanks for posting this.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#82

Post by themartorana »

saidajigumi wrote: post #75
mrb wrote: post #18

Three weeks ago I reverse-engineered my garage door opener wireless protocol. I probed the remote's PCB with a Saleae logic analyzer and found it was a 12-bit code ASK-modulated at 390 MHz with bits encoded as sequences of 10 kHz and 20 kHz pulses. I bought a $13 spare remote to hack it and control the RF transmitter section from my computer through an FT232 sending the ASK signal. I just cut off the digital signal t…

> But there is probably no interest... FWIW, this sounds like a hook around building a business for "next-gen" garage door openers. Security, quality of build, and convenience are among the factors that could be pitched to early adopters. Heck, this even feels like something that the right small team could work into a really sharp Kickstarter pitch, if so inclined. One tricky problem is that garage door openers tend…

Also, is strong security something people expect out of a garage door remote? It's never been a feature, as far as I can remember.

Not that there isn't a market of people who do want for security in their remote, or would but don't yet know it...

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#83

Post by Cerium »

mrb wrote: post #66
Cymen wrote: post #50

Earlier quoted context omitted.

Somewhat of a tangent, but I am concerned about the MITM attack on car locks [1]. This kind of attack is being used in my neighborhood in Oakland, California and no doubt other places. I read the reports of "someone is breaking into my car but no windows/locks are broken". Then a couple other people on NextDoor chime in with the same thing and one person reports a woman who is walking around the neighborhood and appe…

Yeah, a car's passive entry system can definitely be exploited by relay attacks. Here is an academic group who demonstrated it: https://eprint.iacr.org/2010/332.pdf The most obvious way to mitigate is to have the car require the key to send the first bit of the response at most N nanoseconds after the last bit of the challenge is sent over the air. Because of the speed of light this assures the key is within a certai…

There are super low power accelerometers with wake on movement. Simply require the key be recently moved about to activate the door. If the key is not awake, it can't answer any challenges.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#84

Post by ahlatimer »

Joky wrote: post #33
jandrese wrote: post #7

Earlier quoted context omitted.

My parents did the thing where they put keyed deadbolts on all of the doors. So when someone wanted to break in they broke the glass on the door, discovered the deadbolt, broke the glass on another door and discovered the deadbolt, then broke the glass on a third door before yet again being foiled by the deadbolt. Then they broke a window and stole our stuff anyway. Apparently they were professional thieves too, sinc…

It reminds me of a friend that never lock his very old car so that no-one will break a window to see if there is something to steal inside.

A buddy of mine did this in his '70 Karmann Ghia, which, even if the door was locked, was easy to break into with a belt through the window that didn't roll all the way. Someone still broke the window and tried to steal the broken cassette deck that was in it. This was in the late '00s, so I'm not even sure what they were going for there. That cassette deck couldn't have been something you'd even readily be able to give away.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#85

Post by LukeShu »

kleiba wrote: post #27
mrb wrote: post #18

Three weeks ago I reverse-engineered my garage door opener wireless protocol. I probed the remote's PCB with a Saleae logic analyzer and found it was a 12-bit code ASK-modulated at 390 MHz with bits encoded as sequences of 10 kHz and 20 kHz pulses. I bought a $13 spare remote to hack it and control the RF transmitter section from my computer through an FT232 sending the ASK signal. I just cut off the digital signal t…

Well, it seems that from the point of view of Genie, if it's required to send the correct code N times in a row, acceptance should be aborted if that is interspersed by any wrong code. In that case, a De Bruijn sequence wouldn't work.

Because noise and interference. You don't want the neighbor opening his garage door to abort yours--your code and his would be interspersed, but you both still want your door to open.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#86

Post by LukeShu »

themartorana wrote: post #82
saidajigumi wrote: post #75

Earlier quoted context omitted.

> But there is probably no interest... FWIW, this sounds like a hook around building a business for "next-gen" garage door openers. Security, quality of build, and convenience are among the factors that could be pitched to early adopters. Heck, this even feels like something that the right small team could work into a really sharp Kickstarter pitch, if so inclined. One tricky problem is that garage door openers tend…

Also, is strong security something people expect out of a garage door remote? It's never been a feature, as far as I can remember. Not that there isn't a market of people who do want for security in their remote, or would but don't yet know it...

Absolutely; everyone just assumes it's already secure, or at least as secure as the deadbolt on their front door.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#87

Post by fapjacks »

I created a very similar device when I was 17. Back then though, most people with openers had analog remotes. This was one of the first times in my life I ever used (and subsequently purchased) a frequency counter. Oh, what excellent memories.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#88

Post by fapjacks »

greggman wrote: post #32
kbenson wrote: post #8

Earlier quoted context omitted.

Exactly like computer security, it's not about making it impossible to gain entrance[1], it's about making it both inconvenient enough and require enough skill that it takes longer or is more noticeable, making it more likely the intruder will be noticed, thus raising the likelihood they will be caught. That said, a few seconds is a pretty low bar. Commodity locks should be better than this, for all our sakes. 1: Thi…

I don't know what's normal now but a long time ago, 1997, I moved with a complex with 300 garages each with a remote. I opened the remote to change the battery and noticed only 8 switches for the code. 256 codes, 300 garages, drove around the complex opened 2 other garages. Even at 12 bits with 300 garages the odds are very high of a match http://en.wikipedia.org/wiki/Birthday_problem

Weird. I did something very similar in the same year.

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#89

Post by fapjacks »

derefr wrote: post #35
stealthyb wrote: post #29

Earlier quoted context omitted.

This is a much more accurate than the old "Locks keep honest people honest" saying. If you consider yourself an honest person, ask yourself how many times you've tried to open doors to random houses as you walk down the street. If you found it unlocked, do you rob the place? If you need a lock to keep you honest, you may want to reevaluate your values.

The phrase is rooted in a very old memeplex, the part where religious morality and sociopathy overlap. Most ideas revolving around the concept of "putting the fear of God into someone" aren't actually for regular people with empathy. They're for sociopaths. It seems that sociopaths used to be seen as just completely normal people, undifferentiable from everyone else—and much of "morality" is actually an attempt to cr…

Right, you're exactly right, but you also seem to know a bit about sociopaths, and so it surprises me that you are implying that we don't see sociopaths as normal people these days. I've had very personal run-ins with real, genuine sociopaths in my life, and most people just have no idea that there are these people just totally walking around being treated like normal human beings. Sociopaths are not human beings, I say, because what is humanity but our empathy? And sociopaths do not have it, ergo...

Re: OpenSesame – A device that can open fixed-code garage doors in seconds

#90

Post by patcheudor »

nickbauman wrote: post #53
mrb wrote: post #18

Three weeks ago I reverse-engineered my garage door opener wireless protocol. I probed the remote's PCB with a Saleae logic analyzer and found it was a 12-bit code ASK-modulated at 390 MHz with bits encoded as sequences of 10 kHz and 20 kHz pulses. I bought a $13 spare remote to hack it and control the RF transmitter section from my computer through an FT232 sending the ASK signal. I just cut off the digital signal t…

A friend who lives in a wealthy neighborhood here had their garage broken into electronically more than 10 years ago. So clearly some people have known about it for a while. The local police claim the thief probably "listened" to their garage door opener open the door at least once to get in, as opposed to brute forcing it.

It's not uncommon for thieves to go to open houses in nice neighborhoods when a property is for sale & copy the dip-switch codes. This also happens when homes are under construction. No one ever thinks about changing their garage door opener code.
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