Public-key Cryptography - An Idea For a More Sophisticated Dash Camera

Norm I. Leaky

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I gather that the main goal of a dash camera is to capture evidence of an incident so that you can use it to your own benefit. However, some may be worried that their camera might work against them. It's not hard to imagine a scenario where video recorded by your camera is confiscated and used against you, so for people who want to guard against that, I suggest that a solution could be a camera that incorporates Public Key Cryptography.

Public-key cryptography, also known as asymmetric cryptography, is a class of cryptographic protocols based on algorithms that require two separate keys, one of which is secret (or private) and one of which is public. Although different, the two parts of this key pair are mathematically linked.

PGP is a popular cryptographic package that has been under continuous development for about 24 years and includes public-key cryptography, using an open standard. There are other such programs available as well, and many of them are free. A camera could be programmed with an optional feature where a public key could be stored in its memory and used to encrypt video before it's written to memory. The only way the video could be played back would be to decrypt it with the private key that was generated on your computer along with the public key. (The private key is normally stored in an encrypted, password-protected format.)

For marketing purposes this feature would probably be configured as an option that could be ignored by users who found it to be too complicated, but would be available for people who wanted to use it. The only drawbacks I can think of are that the camera would require more capable computer hardware, and, of course, the camera would not be able to play back video that it had recorded.

The more I think about it the more it seems like an obvious idea, which means that it might already exist. If it does then I guess I'm in for a little embarrassment, but I looked at a lot of different dash cameras and haven't spotted anything like this.

Norm I. Leaky
 
You'll need a more complicated hardware ...so, more expensive.
 
You'll need a more complicated hardware ...so, more expensive.
Not at all! Why do you think that? It's possible that it would require a faster processor and more memory space for the firmware, depending upon how the camera was originally engineered, but it's very possible that it wouldn't require either. New firmware alone may or may not be sufficient, but in no sense would it need "more complicated hardware." Videos are currently compressed by the camera and converted to formats like MOV, MP4, etc. before being written to storage. The additional step of encryption would be trivial compared to that.
 
Not at all! Why do you think that? It's possible that it would require a faster processor and more memory space for the firmware, depending upon how the camera was originally engineered, but it's very possible that it wouldn't require either. New firmware alone may or may not be sufficient, but in no sense would it need "more complicated hardware." Videos are currently compressed by the camera and converted to formats like MOV, MP4, etc. before being written to storage. The additional step of encryption would be trivial compared to that.

Yeahhhhh.....no....it would be a lot more complicated. Here's why. You're asking a processor that is build for videos and images to now encrypt. Architecture changes, processing power changes, firmware interaction changes, access points changes, basically everything changes. You can achieve it with current technology but you would have to have a much bigger car camera than most people want. The chips are getting smaller and better but at the moment it's just not viable. Sorry.

Dan
 
The current chips don't have the bandwidth for the additional encoding and functions that would be needed and they would run even hotter than they already do now.

I've noticed over my last two years as a member here that newer members often come up with wild fantasies about capabilities they would like their dash cams to have that are either entirely impractical and/or would make for a dash cam that most people couldn't afford or wouldn't buy. Sometimes I think we need a new sub forum for "Fantasy Dash Cams". In this case, imagining "a scenario where video recorded by your camera is confiscated and used against you" seems unlikely to me. I don't believe there has ever been a single report of such an occurrence even vaguely like that here on DCT. I believe such practice where video is confiscated would result in a court battle, at least here in the US where we still have a 5th amendment last I checked. There are really no tested laws along these lines on personal sousveillance as yet. The longer I've used dash cams, the longer I find the KISS principle (keep it simple, etc) to be the most practical and reliable. All the bells and whistles become superfluous with good video, audio and rock solid reliability becoming the primary goals. It is for this reason that I still keep coming back to the Mobius as my favorite camera.
 
Well, let me put it this way: If the idea isn't viable then any knowledgeable engineer who's exposed to the idea will know that it's not plausible and won't pursue it further. But if it does turn out to be viable then there's a chance that someone will go ahead with it, but only if he expects it to sell.

So what I'm really curious about is whether there would be much interest in such a camera if it did exist.

And "Dashmellow", you posted just before I did so I didn't see your post. Thanks for the warm welcome.
 
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I tend to believe that you give government an inch, they take a mile. The fact no known cases of dash camera confiscations exist doesn't mean it isn't (or won't) happen. I recall one incident where an off duty cop in NY drew a gun on a driver who went the wrong way on a one-way street. The cammer backed his car up at first not realizing it was a cop. As soon as he did, he told the cop it was being recorded. The next words out of the cop's mouth "Good, then I'll confiscate the video". Ultimately, in that stop, it was nothing more than bluster, but still...

I've seen at least 4 cases now where PD's have confiscated quad copters from citizens flying them around police stations. Cell phones have been confiscated after the cops didn't like being recorded - with a very difficult time getting them back.

So, it's not entirely unreasonable to assume dash cameras will fall under the same level of scrutiny as their popularity and prevalence increase.

I would wholeheartedly support a camera/file structure that would prevent unauthorized viewing.
 
If you really would like to keep videos to yourself then the solution is very simple:

1. Use custom flash drive formatting (not FAT32, obviously). It is quite easy to make a completely custom format or if not bothered with that, just use raw flash sector reads/writes. If anything, the raw access will make dash cam software run faster as only limited amount of middleware will be needed.
2. On camera, add "set password" feature.
3. When dumping data stream to flash, record password in the file/sector header.
4. Create custom PC application for data retrieval. This application must be able to collect password from user.
5. When data stream is requested by PC, camera firmware shall request password first and if it doesn't match the one in file/sector header, refuse.
6. PC app shall clear header from password and produce playable video file (basically, just use container; AVI, MP4 or whatever needed).

This way no extra workload is required on camera micro.

Note that this approach will only withstand soft attacks. Anyone knowledgeable enough or with access to right information could hack this. But as a basic deterrent it'll work fairly well.
 
There was a recent thread about whether dash cams should be compulsory, and as various concerns were raised I was thinking exactly the same thing - that encryption would remove a lot of the problems.
I'm not sure that encryption is such a heavy burden compared to the task of video processing/compression, so it may not be that difficult. Ideally one algorithm would perform both functions at once.
Bear in mind that some USB memory sticks have encryption built in. They might even be able to put encryption directly in a micro SD card. Not saying that's the best way (might be too slow) but there are possibilities.
Even if it weren't possible now, technology improves quickly.
 
You can get encrypted memory, a lot of police cams use this method, not practical for dashcams though based on current technology
 
We use things like the Datalocker type USB HDDs which have encryption built in and are accessed via a PIN you enter on the front screen - they're not cheap like @jokiin says and in the HDD space they can quadruple the price. Getting all the fancy certifications isn't cheap :)

DL3FE_600x600.png
 
“Cops may be entitled to ask for people’s names and addresses and may even go as far as subpoenaing a video, but as far as confiscating the camera on the spot, no,” said Marc Randazza, A First Amendment attorney based out of Florida and a Photography is Not a Crime reader.

Bert P. Krages II, the Oregon attorney who drafted the widely distributed The Photographer’s Rights guide, states:

“In general, police (in the US) cannot confiscate cameras or media without some sort of court order. One exception is when a camera is actually being used in the commission of crime (e.g., child pornography, counterfeiting, upskirting).”

What could people do to prevent police from illegally confiscating their cameras?

According to Randazza, “Probably not a whole lot,” “You don’t want to get into a situation where you are refusing to comply with law enforcement."

But what can you do if you’re stubborn and have a tendency to refuse unlawful orders?

“Make sure you have an attorney that specializes in Constitutional law,". “Make sure you have his cell phone and home number. Sometimes calling an attorney on the spot can be helpful.”

The message? Encryption for dash cam video would be a good idea if it were practical and affordable.
 
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Alternatively, use a camera system that is as stealthy as is possible. DO NOT mention cameras or recording to anyone at any time whilst you are in a vulnerable position.

Unless a copper actually sticks his head in your car & has a good look around then he's not going to notice a camera pointing at him if it's unobtrusive.
I've been directly involved with a few incidents lately & in every case, the idiot has been too busy waving their arms around & trying to pass the blame to even notice my little old Mobius hiding behind the sunshade next to my rear view mirror.
And their version of events to their insurer confirms that they never spotted the camera or even suspected their stupidity was all on cam.
 
Alternatively, use a camera system that is as stealthy as is possible.
That's called Security Through Obscurity.
Security through obscurity is discouraged and not recommended by standards bodies. The National Institute of Standards and Technology (NIST) in the United States specifically recommends against this practice: "System security should not depend on the secrecy of the implementation or its components."
It might be a good idea to keep your camera as inconspicuous as possible, but not "alternatively", meaning that you regard it alone as a complete solution to the problem.
 
That's called Security Through Obscurity.
It might be a good idea to keep your camera as inconspicuous as possible, but not "alternatively", meaning that you regard it alone as a complete solution to the problem.
Isn't this aimed more towards CCTV for security of premises and in public areas? The idea being to make the cameras as obvious as possible in order for them to act as a deterrent?
A dashcam isn't there to deter thieves, it's there to act as your independent witness.
 
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