Comment by MichaelCrawford | Hacker News Reader

Comment by MichaelCrawford | Hacker News Reader

MichaelCrawford

I've been puzzling over a Killer App for a little while, but just don't have the headspace to deal with it. Take The Money And Run:

Write a mobile app - or maybe crowdfund a gadget - that would be an always on video camera, or perhaps just an audio recorder with a sometimes- but not always-on camera.

This would be done in such a way that it is simply not possible to erase the recording, not even if law enforcement confiscates your device. The most-straightforward way would be to upload it to a server however law enforcement could take your entire server, or block access to it &c.

Worse who ever operated the server could be subject to prosecution, say for enabling wiretapping. Yes, I know. :-/

However a solution would be for that server to be a Tor Hidden Service. That would make it difficult, maybe impossible to physically locate the server or its admins; it would also make it more difficult to block the communication between the recorder and the server.

Commonly overlooked is that it's not enough simply to operate a hidden service; if someone does grab the actual box, then they've got your filesystem. For this to really work you need a fully-encrypted disk. But then you have the problem that the OS as well as the hidden service require private keys. If you store them right on the box then you lose.

Possibly Trusted Computing would help somewhat. However another way would be for, when the OS boots, it cries out for help in some surreptitious way, say by posting a racy JPEG on imgur. When an admit sees that JPEG show up on Reddit, then he transmits the secret keys to the server.

There is also the problem that, were these recorders always on, then they would record things that anyone would want to be private. Typically we would want whoever possessed the device to choose which recordings to release to the public; however if they were required to do so under a subpeona, again we lose.

So there should be more than one person making the decision. Whoever has a legimate reason to want privacy, as well as someone who can deny a subpeona with complete safety, in principle the server admin.

This outline doesn't scale at all well. I've been puzzling over it for a little while and I can see that it could be made to scale.

But this is the very first time I've written down any of these ideas.

If you can make something of this, More Power To You.

A device that costs money, that you have to carry with you at all times, that you have to have connected to the internet, and you're likely to never use... I get your goal, but I don't think it's practical in the way you're thinking.

There are phone apps which do some of what your suggesting, but leaving them on all the time would mean that you would have to have an unlimited data package and lots of spare batteries.

That's a good point.

I did consider that one cannot always get on the Internet, but I didn't mention it in my writeup. The device could upload the recording whenever the Internet was available.

That would leave the problem that the cops know you've got such a gadget, so they prevent you from going to a wifi spot. For this we use the kind of mesh network as was used in the Hong Kong protests a few months ago. I think they didn't write that app themselves, it was already available from the App Store or Google Play.

Most phones have wifi, bluetooth and 4G. If any one of those can connect - somehow - to the Internet then we can upload.

The problem with battery life would be hard to solve on an actual phone but not hard at all to solve on dedicated hardware. A very, very large chunk of your power consumption goes into managing hardware security and virtual memory.

If you had no security at all, and no virtual memory, then you use quite a lot less power. That's quite common with embedded applications, such as TI DPSs running SYSBIOS (previous DSP/BIOS). I have some experience with DSP/BIOS it would not be hard at all to make a device the size of an iPhone that could run for a week or two between recharges.

The device would be a lot more acceptable to most people if it were not plainly visible. Suppose the camera lens could be clipped to your shirt, but the rest of the device is in your pants pocket or your purse, with a bluetooth connection between the two.

I fully understand there are many problems with this concept, but solving these kinds of problems is what engineers actually do to feed their hungry children. :-D

The problem to be solved here, as I understand it, is accessing the recording after someone takes the recording device away from you, and possibly also attempts to delete your recordings.

You don't need to upload to the cloud here. You just need to upload to a storage device that cannot be easily recognized as the upload target for the recorder, and would not typically have probable cause for a search.

These could be attached to the recorder using a wide variety of short-range wireless communications technologies. Maybe your pinky ring has a microSD card under the gaudy cabochon, and connects using IEEE 802.15.6. Maybe you get a parylene-coated implant in your beer belly. Maybe your eyeglasses can store 256 GB. Perhaps the label on your underwear can store more data than just your name. Or one of the keys on your key ring does not actually open any lock.

Maybe the "delete" function in your device's UI also activates a piercing audible alarm that screams "SPOLIATION! SPOLIATION! SOMEONE IS TRYING TO DESTROY MY EVIDENCE!" and the real data-destruction function requires a pre-authorized device to activate.

The device itself would, of course, need a decoy SD card in it somewhere. People tend not to stop looking for something until they find it.

As for the recorder portion, it would have to be plainly visible to be legal in all US jurisdictions. Also, you need something obvious for the bad actor to take, so that he can believe that he has confiscated both your recorder and your recent recordings.

The data are the important parts, if you can give your attorney a recording of the cop illegally seizing your camera, it is a lot easier to get it back.

Uploading that much video / audio via tor wouldn't really be feasible with the current infrastructure.

I'm hip to that but I expect a solution could be found.

The main problem is that it is risky and expensive to operate an exit node. It's not a big deal to have an internal node.

I expect such an app would be quite popular; if one were able to calculate how much server capacity was required for each recorder, then a retail price could be found that would keep the network within capacity.

Another possibility is that while I assert it would be best to always be recording, sometimes it would be acceptable to do so in low fidelity.

High fidelity audio these days is quite compact.

Had better audio recording been present at JFK's assassination, there would be no doubt as to who fired the shots. Today's Ogg Vorbis or MP3 would be great for that; back then they were using reel-to-reel recorders on police car radios.

Perhaps an accelerometer would help. If nothing bad is happening one wouldn't expect there to be much acceleration. But if you hear a scream or a gunshot, even if you don't aim your phone at it you are startled so that you jump up, look around or maybe even run away. At that point the app would increase its video fidelity - or use less compression.

Most of the time it would use high compression, low resolution or monochrome.

This kind of video doesn't really need to be in color. 8-bit grayscale NTSC video his highly compressible

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