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Researchers find it’s easy to hack traffic lights
- thirdtruck 12y agoI'm almost jealous. Back in my weekly Shadowrun cyberpunk roleplaying game, super-secure traffic light systems complicated a lot of our missions.
- cortesoft 12y agoI remember seeing a talk at RSA a couple of years ago about the plausibility of the "Italian Job" type attack, where they make all the lights green and cause everyone to crash.. they said that sort of thing was impossible because there is a mechanical switch that prevents both lights from being green at the same time. So at least an attacker couldn't cause those sorts of accidents, even if they could totally mess up the system.
- datasmash 12y agoThat's pretty good foresight by whoever designed them.
- crazypyro 12y agoNot foresight. It was a limitation of the hardware at the time. It's also a relic of the past and no longer accurate as modern boards don't possess the same limitation.
- dunmalg 12y ago>Not foresight. It was a limitation of the hardware at the time. Nonsense. Even mechanically timed lights can be wired to illuminate any arbitrary set of lamp in either direction. The only difference between then and now is that back then you had to physically move wires, whereas now it's software switched.
- crazypyro 12y agoWell, yeah. I phrased that poorly. I'm just saying there is very little chance the designers foresaw the possibilities of people hacking into the lights when they were transitioned into computer controlled. I imagine it was done because it reduced the chance of a bug in the hardware creating an ambiguous signal.
- toomuchtodo 12y agoThis was true back in the mechanical era when a drum was used for control; you physically could not engage multiple directions as green at the same time. I do not believe this is the case now that control is done with software/firmware. Example Controllers: http://www.mccain-inc.com/controllers.html http://www.mccain-inc.com/controllers.html
- ams6110 12y agoThe controllers may be able to order it but the lights are supposed to be wired so it's impossible. E.g. grounding the green lights thorugh the cross direction green lights so you can't illuminate green in all directions at once. Or something along those lines. edit: s/opposite/cross/
- azinman2 12y agoIt would make good sense to harden it against failure, which can come in any form (software, mechanical, etc)
- dm2 12y agoAnother method would be to setup a vehicle or box on the side of the road that emulated an emergency vehicle which instructed the light to change to green in the direction that you wanted it (could also be used to change lights to red if put in the perpendicular direction). http://en.wikipedia.org/wiki/Traffic_signal_preemption http://en.wikipedia.org/wiki/Traffic_signal_preemption I'm not sure which method is most common. The wikipedia article says that IR, acoustic, visible lights, and GPS can be used to change the lights. It would be fun to experiment with different methods of changing them, but would undoubtedly be illegal. Apparently it's not illegal federally to use these devices to change lights, it might be legal in some states. http://en.wikipedia.org/wiki/Mobile_Infrared_Transmitter http://en.wikipedia.org/wiki/Mobile_Infrared_Transmitter http://www.themirt.com/ http://www.themirt.com/
- iancarroll 12y agoIn Troy MI they have infared traffic preemption. Michigan has a state law making it illegal to mess with them.
- dzuc 12y agoProbably the only time this image will be relevant on HN: http://oaknyc.com/blog/wp-content/uploads/2013/08/Hackers3.jpg http://oaknyc.com/blog/wp-content/uploads/2013/08/Hackers3.j...
- b_emery 12y agoThis quote is pretty classic: > According to the paper, the vendor responsible stated that it "has followed the accepted industry standard and it is that standard which does not include security." Clearly, the 'vendor' lacks a PR team.
- anigbrowl 12y agoI bet they have one when they want to complain about the amount of red tape they have to deal with as part of the bidding process...
- soperj 12y agoMore than anything I'd love to use this to actually improve the way the lights are run downtown in my city. It's insane that they actually use them to make people spend longer in the downtown corp. (when one turns green, the next turns red, there is literally no flow to traffic and would be faster going through a number of stop signs.)
- sixothree 12y agoYes but people spending more time in traffic equals more tax dollars from gas.
- privong 12y agoAre city-imposed gas taxes common? Generally, I think of there being state and national gas taxes, but not (usually) city taxes.
- aetherson 12y agoIt's also not THAT MUCH gas. Cars don't use a ton of gasoline while idling. This page (http://greenactioncentre.ca/living-green-living-well/myth-2-its-better-to-idle-your-car-than-shut-it-off/ http://greenactioncentre.ca/living-green-living-well/myth-2-...) asserts that cars use 1/10 to 4/10ths of a liter of gas per 10 minutes of idling. Call it an average of .3 liters, which is 0.08 gallons. If you spend 20 minutes a day (a HUGE amount) at red lights, and then your city doubles the length of all red lights, so now you're spending 40 minutes a day (absurd), that means that each day you spend an additional 0.16 gallons. So at $4 per gallon, that suggests that your cost (not the city's revenue) for this absurd scenario is $0.66 per day. If the city has a completely ridiculous 10% gasoline tax, that suggests that it's getting $0.07 per resident per day. Or $25 per year. This may not be the most difficult way for a city to raise $25/resident/year of revenue, but it's certainly in contention for it.
- gress 12y ago$25 per resident per year is significant, $25M a year in a city of 1M. And how is this 'difficult'? It seems like it's a trivial software modification - certainly not $100,000 worth of work. I agree that it's a bizarre and horrible way to raise revenue, but your calculations actually make it look quite straightforward to implement.
- UweSchmidt 12y agoProbably stating the obvious, but messing with traffic signs not a good idea for a fun hacking project. I heard of someone going to prison for removing a stop sign, obviously being held responsible for the accident that ensued.
- wglb 12y agoFrom the second paragraph of the article: The exercise was conducted on actual stoplights deployed at live intersections, "with cooperation from a road agency located in Michigan." So this was done with permission.
- stephen_g 12y agoAs someone who works on traffic control systems in a different country, I can definitely believe a story! We make security a priority (even with full network access you couldn't control our system) but a lot of third party systems are ridiculously rubbish and a lot of Government agencies only make token efforts at security.
- zanok 12y agoThe original paper is here: https://jhalderm.com/pub/papers/traffic-woot14.pdf https://jhalderm.com/pub/papers/traffic-woot14.pdf
- userbinator 12y agoWireless!? On traffic lights that presumably have to be connected to a power source anyway? It seems to me that the cost of running an additional network cable to each light (or even just sending the control through powerline networking) would be negligible, and it would prevent much of the attacks described - physical "hacking" would be required, which is more difficult to do and easier to detect. This seems like yet another case of large increases in complexity (and thus attack area) for little to no benefit, as is all too common in systems these days.
- elithrar 12y agoNote that it is entirely possible your power source (often a metered source from a utility) may be distinct from your comms source, if you even have comms in that location at all.
- tripzilch 12y agoSometimes emergency vehicles need the ability to affect traffic lights. I'm pretty sure I've seen this happen once (in NL), at an intersection with a very predictable traffic light sequence (some intersections use sensors, others simply follow a set pattern), an ambulance came by, sirens blaring, and the whole pattern pretty much skipped a "turn".
- walls 12y agoThis has historically been accomplished by sensors on the lights and emergency vehicles flashing a specific pattern, not wifi.
- snarfy 12y agoI was under the assumption traffic signalling was so horrible because it was a simple timing based system. Knowing they are all networked, accessible, and controllable from a central computer infuriates me, not because they are hackable, but because the software currently running them is so, so horrible. It's good ol' 'government' software.
- fiatjaf 12y agoWell, this is a difficult thing for a software to do.
- TeMPOraL 12y agoObligatory xkcd: http://xkcd.com/277/ http://xkcd.com/277/. That is, as a driver, one isn't in a position to judge whether traffic lights timing make sense, because they're optimized globally to ensure best traffic throughput in the whole city.
- walls 12y agoWhen you're sitting at a red light for several minutes at one in the morning with no cars visible for miles, it doesn't take a traffic engineer to realize that intersection is not working optimally.
- snarfy 12y agoBut as a software engineer, I can certainly say that comic is wrong. After enough short sighted releases, mountains of technical debt, poor coding standards, and general apathy, I do not believe the engineer depicted in the comic is accurate. "Hours of simulation" and "took me a week to work out the timing sequences". No. No government paid software engineer spent a week working out the timing sequences. They hacked out something as quick as they could to meet the ridiculous deadline they were given, and then had a good laugh about fixing the process during the retrospective meeting.