Emergency stop signal should be easy to send when it is needed.

Most trains have a emergency brake lever inside which is also very easy to abuse, but is there for safety. It is better to enforce harsh penalties for abuse.

In Germany, in addition there is yet another emergency signal - if you need a train to stop (say, because someone fell into the tracks) and you can see the train (so no time to call 112), wave your hand in a circular motion [1].

[1] http://www.tf-ausbildung.de/SignalbuchOnline/sh3.htm

Same in Poland, though here you can also use white lantern, if you don't have red one.

Harsh penalties are ineffective and irrelevant in terrorism and warfare situations.

Here I don't think that this signal system is designed to be used by the public. I'm guessing that there are transmitters installed and operated by the railways and perhaps police/emergency services but no-one else.

I am sure that the system will now be upgraded to include cryptographic authentication.

And that will sooner or later result in loss of life. Certificate not updated? Oops...

In this case I am pretty sure that a single organisation controls the whole system, transmitters and receivers. So I see no reason why they would update one side but not the other. There has to be a minimum level of competence and enforced procedures to run any important systems...

That's not how safety systems work.

Ever walked around in a factory? Those big red mushroom buttons everywhere actually work. Absolutely nothing is going to stop you from hitting one of them. It's not unlike the social contract: the assumption is that you too are kept safe by others.

Abusing such systems is the lowest of the low, and will get you in serious trouble. As would be sabotaging fire fighting equipment, arson, bomb threats, throwing stuff onto the highway and so on. The fact that you can't see any reason means that you are probably not in charge of safety anywhere. The battle is so asymmetrical that you can't win unless people stick to the assumption that their lives are valuable too. If that is no longer the case you are technically at war.

This is why suicide bombers have an easy time of it: they have broken out of that social contract and are willing to give up their own lives to take the lives of others. You simply can not effectively defend against this unless you are willing to throw out the social contract and become a police state yourself (or suffer eventual loss of life).

The minimum level of competence to run an important system (to put a train in motion, for instance) is definitely there. But to stop an important system should need no competence, it should just require presence and action. Any other requirements are not going to be secure (because too many people need to have access to such systems, including all of the public) but will cause the critical part to fail just when it is needed.

Obviously in a factory people who are let in are vetted and authenticated to start with.

Here we're discussing a radio transmission (from what I understand) in the wild that can come from absolutely anyone and anywhere and stop a whole train. There is no reason for this not to be secured.

I didn't claim that there should be a special competence to remotely stop a train, and indeed we may want something as simple as a big red button. But not anyone should be able to push that button and there should obviously be competence to run the system behind the scene as per my previous comment.

> Obviously in a factory people who are let in are vetted and authenticated to start with.

Factory workers are not vetted beyond being able to perform some function on behalf of the factory owners / operators. That can be as much as having finished grade school. On your first day you have the run of the place.

> Here we're discussing a radio transmission (from what I understand) in the wild that can come from absolutely anyone and anywhere and stop a whole train.

Oh no! Such radio transmissions have been the norm for decades and plenty of such older systems are still in use all over the world. Abusing such systems is easy. Upgrading them properly is costly and carries risk so the default is to leave things as they are.

> There is no reason for this not to be secured.

Well, why don't you propose a system that is 'secured'? And then I'll show you fifty ways in which your so called secured system can be 'hacked'. For instance, pre-emptively by stealing some of the gear.

There are fall-backs for all of those and the final fall back is flares and hand signals which every railway man hopes to never see in their lives. Fucking with infra is easy. Creating systems that are still just as safe but that are secure isn't easy at all: it is impossible. As every hacked website proves. And even if you could: the next thing that would happen is that these jerks would derail the trains instead of stopping them because that too is stupidly easy.

At some point we all rely on each other not to do bad stuff.

We know that a lot of our critical infrastructure is vulnerable, as this article again shows. This may have been "the norm" for decades but this has to be fixed. Unfortunately it often takes a catastrophe for things to be fixed.

At least here there was no catastrophe but still enough noise at a sensitive enough time that, again, I am sure that those systems will be upgraded.

Also, we're discussing securing infrastructure against threats up to state actors. They don't care about harsh penalties unless these are painful counter-attacks.

As far as I'm concerned the system worked exactly as designed. Nobody died, all trains stopped safely for a minute or so. Props to whoever designed the system and to all of those involved for keeping their heads cool.

What will most likely happen is that we will see more such acts of sabotage, against these and other systems.

Some suspects (Polish nationals) have been arrested:

https://www.i24news.tv/en/news/international/europe/16931682...

Ok, here's a different example.

Defilibrators, strategically positioned at places where a lot of people congregate. Such as train stations or city centers.

Herearound those are not locked. There's nothing stopping you of taking it out and toss it into the river.

The social contract is such that you just don't fucking do it and frankly, I never heard of such a thing happening. And yes, we have our shares of assholes.

Contrast that to the UK, where they are under lock and code. You call an operator explaining the emergency and she may unlock it.

There are two problems that I can see (and probably more). The communication device adds another layer of potential failure. And those two minutes it takes to unlock the device may be the difference between life and death.

I, for one, know in which kind of society I prefer to live. Even given the very occasional asshole who breaks that contract and abuses the accessibility of that life saving device.

You cannot compare access to a small medical device in public places to being able to stop whole trains remotely...

Sadly, given the current situation, we'll probably have to migrate from the current (easy to use and available) system to something more secure (and fragile).

Some people will die, but if that happens again there's not much choice.

No, I don't think we should. What we should do is hunt these perps down and take them out of circulation for a long long time. Because it isn't possible to make a system both easy to access and secure at the same time and if the price is that people will get killed who have nothing to do with any of this then we will end up losing our critical infrastructure just as sure as if you bombed it.

It's very hard to find a source of a radio signal sent from a middle of nowhere (having only a few trains to trinagulate). Of course we should do this, but if someone starts abusing this to raise chaos in the country, we may have no other choice. And we have an enemy country very interested in causing problems nearby.

>Because it isn't possible to make a system both easy to access and secure at the same time

Not right now, but since 2009 we're implementing GSM-R, and we still don't have it. It's not a bad solution, but nobody really cared until the recent abuse happened.

Legacy... hard to overcome that in a few years when it took many, many decades to deploy the original gear. This stuff is quite expensive, deployed everywhere and needs to continue to be backwards compatible while the new solution is rolled out, which is difficult to achieve.

In the UK, the "emergency stop" feature might actually be an "emergency talk to the driver" feature.

Source: I was sitting opposite a family whose small child activated the emergency stop. The train didn't stop.

On a modern train, if you activate the button and the driver doesn't react at all, it will eventually stop the train, but the driver gets a few moments to decide what to do, and in a lot of cases their decision is going to be explicitly "Don't stop" because of the disproportionate number of inadvertent or malicious activations.

On the tube, where (aside from a handful of long distance expresses e.g. to/from Amersham) your train is going to stop at a station anyway in the next couple of minutes they have notices explaining to people that the best way to get e.g. medical assistance is going to be to get off the train at a station, where they can help you, not stay on it and push the emergency button hoping somehow assistance magically teleports to a moving train.

See my other comment. On modern trains, the emergency lever doesn’t stop the train anymore but let you speak to the conductor. The train will only stop if you don’t speak for several seconds or in case of a real emergency.

And tbh, I just can’t see which sort of emergency can happen inside the train that would require an immediate full stop. Even if something life threatening is happening inside, the best option is to call and meet the emergency services in the next station.

> And tbh, I just can’t see which sort of emergency can happen inside the train that would require an immediate full stop.

Trains are multiple vehicles that are somewhat loosely connected. A train segment could be detached from the rest of the train.

https://abcnews.go.com/US/amtrak-cars-separate-boston-bound-...

And other mechanical issues with the train besides (for instance: the train being on fire).

The fact that you can't think of something doesn't mean that you have done an exhaustive search.

In case of a detachment, the train will automatically perform an emergency brake (without the possibility of manual intervention by the conductor).

Trains are fail-safe. They only run because the brakes are held open by a pressured air system running along the whole train. In case of a detachment, the hose connecting the wagons would break, releasing the air pressure and thus slamming the brakes down.

Fair enough, that's a thing I actually knew so I should have not used that example. But a runaway would have much the same effect.

Examples where a passenger-initiated emergency stop would help:

The Eschede crash in Germany: https://en.m.wikipedia.org/wiki/Eschede_train_disaster -- part of the wheel came through the floor into the passenger compartment. The passenger couldn't find an emergency stop, and by the time they'd found a conductor and got their attention (which took minutes) the train crashed.

Trap-and-drag accidents where somebody on the platform gets clothes trapped in the train door and is pulled along with the train as it starts to pull off. If you don't emergency-stop the train within seconds that person is likely to suffer serious injuries or die. Likely the conductor/guard isn't near that door and only passengers will have seen the problem.

You can activate the emergency stop in any train. Just like that, go figure! No security around those things at all, sometimes a thin pane of glass but that's easily taken care of. Or light an emergency flare next to the tracks. If it's that simple you almost have an obligation to show how insecure this is. And you could easily orchestrate this or do it again a short while later on another train.

/s

Whatever happened to personal responsibility? Hackers without ethics (no matter whether acting on their own or for some larger entity) are less than useless.

> You can activate the emergency stop in any train. Just like that, go figure! No security around those things at all

That’s false, at least on modern trains, in France, for what I know.

Any modern train will not stop when you pull the alarm lever.

The first thing that will happen is that you will be in communication with the conductor, then the train will be stopped in only two scenarios : either you are communicating a real emergency or you don’t respond at all to the conductor asking you what happens after a given delay (which IIRC is 10 seconds).

And fwiw, a friend of mine who is conductor explained to me that if you activate the alarm lever by inadvertence, the worst thing you can do is to not answer by fear of having problems. If you say it’s an error, the conductor will just ignore it and continue its day while if you say nothing, the conductor is forced to emergency brake the train and all the trains on the line.

So: just that: you don't need to do anything beyond pulling the lever to get the train to stop. The override is that you say everything is ok, but if you do not the train will absolutely stop.

This is to ensure that if the driver / conductor is incapacitated the train will still come to a halt. And that in turn is because runaway trains have happened.

I don't know the French way, but coming form Germany:

For logner tunnels etc there is an override, where emergency break doesn't break immediately as stopping a train mid-tunnel is most of the time the worst choice. Smoke in tunnel is dangerous. Emergency help can't reach it. Evacuation has confined space. etc. There emergency break rings an alarm with the engineer. If they ignore it, it will stop after a while, but usually they will use intercomm to understand the reason.

A way however you can stop trains on a German train line is by putting a 2kHz electromagnet on the tracks. That will tell the train that it just crossed a red signal and will stop.

Please edit your comment and take that info out. I understand you mean well but spreading this is stupendously risky.

You realise you can just look this stuff up? https://en.wikipedia.org/wiki/Punktf%C3%B6rmige_Zugbeeinflus...

Crusade against Wikipedia that the information is stupendously risky if you think that's a good use of your time.

Yes, I do realize that. The fact that other parties are irresponsible is no reason to join in.

How irresponsible of (gasp) European Commision to publish the exact specification (frequencies and timings of the tones) of the command used in this attack (in Poland):

https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L...

(p. L 342/109-110, or ^F RADIOSTOP)

This is Official Journal, available in all EU languages (at the time).

This is well documented in each railway publication.

Also the risk is .... not existent. To damage railway infrastructure there are way more efficient and simple ways (getting a rail to derail, destroy some signaling cables, ...)

The "attack" here would require quite some investment in equipment (power etc.) and only bring a single train to a realtively quick stop, well in safe margins, where the driver after a quick check with the dispatcher can override and continue the ride, while investigators would collect the equipment.

It's impractical for a stunt (way simpler and more effective: just walk close to the tracks and they will do emergency stops for all trains close by) and ineffective for an attack.

Yes, there are other ways to bring trains to a halt or to derail them. Even so I think it is irresponsible to spread such information further than it has to go, especially on a site called 'hacker news', and even more so in a thread where people are openly arguing that insecure systems should be replaced by more secure ones. Rail infra is not as easy to update as your average web based project and keeping such information out of the hands of would-be experimenters can only be good. No downside, possible upside: easy decision.

> If it's that simple you almost have an obligation to show how insecure this is.

Please don't spread this "white hat hacker" extortion mindset to my neighbourhoods.

I don't even look my door.

Thank you.

Sorry, that should have had an /s appended (I thought it was obvious given the last sentence). Fixed.

Personally I've had it with the so called 'hackers'. They're just criminals. Oh and I think you meant to write 'lock' not 'look'.

Heh ok ye well you never know.

It's always funny when those "grey hats" or similar "it's just a prank bros" find out they're "vulnerable" to a pair of handcuffs, or to judicial findings, or even worse things

I've had a several months long run in with a so-called 'hacker' on HN who is now - fortunately - in jail for something else. This got really tedious and the lack of support was quite frustrating (to put it mildly). I'm sure he thought it was all fun and games. He's threatened swatting people on here, destroying their businesses, families and so on. And all from the relative safety of what he believed to be anonymity.

Such people have no place in society and setting them loose on neighboring countries is inviting a tit-for-tat that we can all do without. Personally I think these attacks are very close to - or already over the threshold for - acts of war.

Then we can also say that pulling fire alarm leaver is hacking.

It absolutely is hacking. It's gaining unauthorized access to a system in a way it's not designed for.

That it's easy to hack makes no difference.