All speed camera fines in doubt

Not sure whether to post here or chit chat.

Sources:

http://www.news.com.au/story/0,10117...1-1242,00.html
http://www.theinquirer.net/?article=25317

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EVERY fine issued by speed cameras could be invalid, after the Roads and Traffic Authority admitted yesterday it could not prove the authenticity of the pictures they take.

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The case revolved around the integrity of a mathematical MD5 algorithm published on each picture and used as a security measure to prove pictures have not been doctored after they have been taken.

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The lawyer argues that the known flaws in MD5 resulted in the prosecution being unable to guarantee that the picture had not been tampered with.

Now I hate speed cameras because I think their placement on motorways etcetera is simply for revenue generating (I've never had a speeding fine btw). I think they should be used in towns where a reduction in speed would have a definite effect on road safety. My joy at the prospect of these cameras being taken down was tempered as the guy being let off was speeding outside a school. The place I think speed cameras should absolutely be placed. :(

for a while our state decided parking unmarked vans on the side of the road with people inside snapping the speed pictures was a good idea...

but ours was shut down (thankfully) becasue a number of police officers, fire fighters, and high level goverment employees were getting too many tickets lol...and the abundance of people flipping off the cameras/egging the vans/throwing soda at the vans etc.

We've got those too. I pass one regularly on a road that resembles an aircraft runway, no corners, no junctions and no history of accidents. Totally against the guidlines for locating cameras as issued by the Gov.

It's now to the point where I brake instinctively whenever I see a white van parked at the side of the road or a man in a flourecent jacket whatever speed I'm doing. So do most other people now which can't be safe.

Revenue generation has always been the argument thrown up by people opposed to this practice. I tend to agree, most municipalities are ONLY interested in that aspect. When I was on one such force, they looked into getting one, and had a company loan the city one for a few months...it was an S10 Blazer (circa 1998, when I worked there). The problem was, the system in the vehicle records all this data (speed data, image, etc.) and you have to send it to the company. THEY process it and send out the infraction notice, and collect the fine if paid via mail. They then keep 50% of the fine for processing costs. So while the idea is decent (use it to supplement the police force, where we can't pay for a cop to monitor every dangerous section of road 24x7), the reality is to cover the initial expense and deliver on the "revenue increase" that the Chief of City manager promises City Council, they have to put it in places like you've both described. :(

As for the SECURITY portion of this discussion...the flaw in MD5 is exactly the sort of lawyerese horsecr@p bulls*** codswallop that ALWAYS gets used in criminal court. There is no real corrolation to the reality and likelihood of a tampered image being USABLE to frame someone into a speeding ticket. It's simply a black and white statement... "Can you GUARUNTEE the image as not tampered with? No? Case dismissed."

Police officers are trained during certification with intolilyzer systems (chemical analysis machines that measure breath alcohol content), that they must make the subject remove any and all foreign objects from their mouth and observe them for 20 minutes before taking a breath sample. If the subject bealches, vomits, etc. during that time, you must have them clear their mouth and begin again. This is a result of case law where it was found that someone chewing piece of bread could, due to the nature of processed organic materials decomposing and breaking down, the subject chewing bread *COULD* register a MINUTE amount of alcohol on their breath, as a result of the bread breaking down. Miniscule, completely insignificant compared to the levels of alcohol that is measured and used in DUI/DWI investigations and prosecutions. But it was that tiny, minute amount that has been used by sleazebag^Usmart lawyers to instill a "reasonable doubt" in the morons^Ujuries that made the decisions.

Now you know one of the reasons I'm not a cop anymore.

Sorry for the huge and mostly off-topic post above. The point that addresses the technical aspect of this discussion is that a schyster^Usmart lawyer will argue that "can you be certain beyond a shadow of a doubt (he'll probably say reasonable doubt) that the image has not been altered?" Even though, to alter an image...or more realistically, to present ANY image...that CAUSED an MD5 collision would do one of 2 things...

1. The replacement image would be drastically different, and thus useless for the intended purpose
2. The modification would be so insignificant that the casual observer (read: juror) would never notice the difference when comparing the edited and original images. (Please note the likely hood of doing this is ridiculously lower, well nigh impossible, I believe.)

But let's all go out and get law degrees so we can argue the f$cking definition of the word IS.

</rant>

Zencoder is right, due to the wraping nature of MD5, the change needs either to be minute (changed a pixel or two) OR something radicaly different. Being able to change the entire license number of a car while keeping the same md5 hash is such a remote posibility that it would be easiest expressed as 0.

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Sorry for the huge and mostly off-topic post above

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Don't apologize, I enjoyed reading about it. I'm curious to know where you used to work. Overhere the deadline for a breathelizer is 2 hrs. Just a field test is not enough, the DA will drop it. Go figure. We have to call highway and wait for them to do the actual test in one of their sites. The entire thing is videotaped. There's always that retard that insists they're blowing...meanwhile there's nothing coming out of their mouths but lies.
The cameras haven't been disputed yet. Not that I know of. But they're so big you can actually see them. I think that beats the whole purpose.

Disclaimer: I do not know the legal procedures and requirements for the country in question, will speak with my understanding of the law where I live. I am not defending the decision nor criticizing it, just asking questions.

We've seen this before. The underlying problem is in general the judges, prosecutors, ( and juries where applicable ) just don't understand the technology. And although this may or may not be the case here, the problem is not just limited to them; the reporters cloud the issue by not properly reporting the essential facts which the decisions were based on but report “ highlights”, and don't ( can't ? ) explain the issues properly.

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Mr Miralis argued that the RTA had to prove the algorithm it used was accurate and could not be tampered with.

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This entire argument may or may not be relevant. Any evidence can be tampered with. But was there opportunity for it to be? In addition to what has already been mentioned, what wasn't explained by the article is why the defense believes it could have been tampered with. ( note, they may not have to prove it was, just could have been. ) If there was no opportunity for it to be changed, it is irrelevant that it could be changed.

The prosecution must prove “ chain-of-custody” with respect to evidence. So just for arguments sake, let's say the cameras send their pictures over the Internet to a server where they are stored, retrieved, then processed. This scenario obviously opens up a number of places where the pictures can be tampered with: the host at the camera, in transit ( MITM ), the server, etc.

So, now speaking to the actual circumstances.
What safeguards are in place to prevent this?
Are they sent over dedicated lines? ( are they transmitted at all? )
Can the photo's on the server be compared to originals at the cameras? ( Are there originals on the camera's host? )
Are the communications between the cameras and servers ( if there are any ) encrypted?
Have there been any breaches to the systems? ( this would also speak to the larger question of “ was the equipment working properly”. )
How do they monitor this?

Were the Admins of the systems and the vendors and manufactures called to answer any of these questions?
Or, was the entire defense based solely on the fact that somewhere MD5 was cracked?

I don't know attorney costs over there, but with a total legal bill of only $3300 how many “experts” did the defense call to verify the photos could have been altered, and to such an extent and still maintain the same hash? Or was the decision made merely out of expedience by a local court without regard to ramifications?

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"It is our understanding that since speed cameras were introduced approximately 15 years ago on NSW roads, not one single speed camera photograph has been capable of proving an offence."

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With a statement like that, where are the vendors and manufacturers? Their reputations ( and future earnings ) are on the line. And if this statement is true, what about those that made the decisions to implement and maintain these systems all these years?

Did the court address what would happen if other algorithms were used?

Is the RTA in the process of upgrading to something like SHA-2 and didn't want the expense of defending something that would not be in use in a few months?

Too many questions.

off topic:
zencoder said

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"Can you GUARUNTEE the image as not tampered with? No? Case dismissed."

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This reminds me of a time I got called for jury duty. After, in sidebar, answering the Defense attorney's question multiple times on whether or not I thought I could be objective with respect to the facts of the case, the Defense attorney then asked me if I could GUARANTEE it. My response was that the only thing I could guarantee was that someday I would die. I don't know why, but the Judge just smiled at me and released me from service. :)

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Mr Lawson had adjourned the case in June, giving the RTA eight weeks to produce an expert to prove pictures from a speed camera on Carlingford Rd, Epping, had not been altered after they were taken.

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But RTA lawyers yesterday told Hornsby Local Court they could not find an expert and the case was thrown out

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Looks more like a failure of the prosecution to get their act together rather than the judge making a decision on the validity of MD5.

Like I said I normally jump for joy when cameras are proved to be unreliable,

http://www.theregister.co.uk/2005/02...ph_school_bus/
http://www.theregister.co.uk/2004/01...ocks_motorist/

but this guy was caught speeding outside a school and should have been nailed.

I read recently that in some areas where speed camara usage has risen, so has the instance of road death. In areas with little or no camara installation, road death has actualy decreased.

Zen and I live in speeding ticket mecca. And we don't even use the cameras. But I agree the MD5 issue is horse balls. Even though I want the systems taken offline.

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Originally posted here by jinxy
I read recently that in some areas where speed camara usage has risen, so has the instance of road death. In areas with little or no camara installation, road death has actualy decreased.

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Hi jinxy,

I've heard similiar cases...probably because drivers are more aware of the cameras and instead of it causing them to be more careful it actually distracts them causing a higher accident rate.

Eg ;)

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Looks more like a failure of the prosecution to get their act together rather than the judge making a decision on the validity of MD5.

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Actually the judge DID make a decision. That is my point. He made the decision to accept what argument(s) the Defense used. He then gave the Prosecution time to respond to the Defense's claims.

However, was that argument
that the photos can be altered
and/or
that there was opportunity for the photos to be altered

A lot of things come into play here, not the least of which could be the necessity for the RTA to divulge publicly their network setup used for the cameras ( which they may not want to do. )

Again, if the setup used was similar to the example I gave and the RTA ( and the vendors ) relied solely on the MD5 to verify the photos then they have a problem because of all the possible avenues of attack. The Prosecution would then have to find “experts” to say what has been said here, that the level of alterations necessary could not have been made ( and I don't know ) and still produce the same hash.

But, ( back to the chain-of-custody thing, ) if the systems are locked down tight and they can ( beyond reasonable doubt ) prove that no one could have gained access to make any alterations then the MD5 issue is irrelevant. Now they would have to bring in their admins, etc. to verify the integrity of their systems and prove the “chain-of-custody.”

Personally, I am glad the legislators here banned the use of unmanned cameras such as this. But what about the “E-ZPass“ that not only records your toll, but the exact time. Since they know the distance between the sensors can they use distance/time to calculate your speed. Last I heard, Officially, they say they don't.

Well, I can't speak about EZPass. I think it would be political suicide to try and charge people for that. A skilled defense attorney could argue a lot of things, including calling into question the accuracy of the EZ-Pass system...and then he'll say if the accuracy of the clocks is in question, how can we be certain that the accounting system is accurate and isn't ripping off hard working truckers?

No, the ruling mentions RTA claimed they couldn't find an expert. That falls one of a few ways:
1. They were unable to find an expert on the subject of MD5 hash algorithm mathematics and accuracy.
2. They were unable to find an expert on the subject who would testify to the accuracy and be able to defend it against the academic work out of China showing MD5 collisions are possible.
3. They chose not to fight this in court, and let it go

It's typical. This sort of standard has been used again and again...it's case law. The term is "precedent". That is why digital photo's were not admissable for a long time; there was no way to guaruntee they hadn't been altered.

It's that 'reasonable doubt' standard. Ah, it pisses me off. Time to get inebriated.

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This sort of standard has been used again and again...it's case law. The term is "precedent".

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Again, I don't know about there, but a case such as this isn't really “ case law”.

I'm sure this defense will be used again since it worked. But the courts are not bound by this decision and may rule the way they wish.

Remember, this was a local court. Case law is usually set by higher courts.

Another judge may not accept the same arguments offered by the defense this judge allowed, which were ...?