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Comment by bri3d | Hacker News Reader

Another interesting part of the Raspberry Pi VideoCore blob is that it implements DRM for Raspberry Pi products: the Pi Camera V2 has an Atmel ATSHA204A CryptoAuthentication chip on it and uses an HMAC+nonce challenge/response system to authenticate with the VideoCore blob when it goes to bring up the CSI interface. Marcan42 dumped the keys from the VideoCore blob and documented the system a few years ago.

According to the Pi Foundation, this is because simple peripherals are too easy to clone and they need to recoup their investment in accessory design.

I was reminded of this while I was researching Twitter speculation yesterday that something similar is done for the DSI interface for displays. I wasn't able to substantiate this - the FKMS (FakeKMS/FirmwareKMS) and proprietary Raspberry Pi video drivers, where link negotiation and backlight control is done in the blob, do only support specific displays. However, it's unclear to me if this is due to driver support or an intentional lock-in. The open-source KMS driver (not yet usable on Raspberry Pi 4) where link negotiation and backlight control is done in the kernel, of course supports anything with a driver.

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>According to the Pi Foundation, this is because simple peripherals are too easy to clone and they need to recoup their investment in accessory design.

I find this completely fair, but then maybe don't call yourself a "charity" and an "open platform" and just be upfront that you need to lock down your hardware to recoup the investment.

I don’t object to the use of “charity” nearly so much as “open platform” in this case.

A charity that gives away some things but not other things is still a charity. A platform that is partially closed is not fully open.

They've always been pretty clear about which parts that simply couldn't open up, due to restrictions beyond their control.

It would be way less of a problem if they would commit to removing the DRM by a certain date. At the very least, they should commit to doing that when they stop supporting the platform and making the proprietary addons to it.

No, this is not fair. If making accessories is not profitable, then don't make them. Instead release the documentation and let others make the accessories.

I understand this as it being profitable to make and sell accessories, but not to engineer the accessories. The engineering is done in the hope of being able to sell the accessory. If they can't sell the accessory, the engineering investment is purely loss.

So, not a charity...

You do realize that most charities sell some things, right?

They don't have to be profit oriented, though. They just have to balance the money flow.

And what is protecting your investment to ensure it is not a massive loss, if not balance their money flow?

Anyway, engineering things to manufacture them and sell for profit is not a charity. It's indistinguishable from normal business.

Also Raspberry Pi SBCs and accessories are made by Raspberry Pi Trading Ltd, not by the foundation. If you look up FCC testing reports, it's all submitted by Rpi Trading. That's not charity even legally.

https://blog.adafruit.com/2021/09/21/raspberry-pi-trading-lt...

Charity, right? You wouldn't know from their own website, because they seem to not publicize their business structure very much. My guess that it's similar to mozilla foundation/co split. Foundation does nothing about the products, it's just a public face. And corportaion does all the product work, and is very for profit.

Charity doesn't mean "has to waste money".

But on the other side if you have a proprietary interface then there will be less accessories and the product will be less attractive for customers.

Yeah, this is a dick move for sure. I had no idea the camera was locked down like this. Just plug in a better quality USB camera and you've bypassed the whole protection. Pointless.

Anyone can make a camera, there are no restrictions. What is difficult are the algorithms for processing the data that comes off the sensor. The RPI foundation developed a complete solution (camera+software) and they don't want to see copycat cameras make use of their investment in image processing software.

I find this to be completely fair game.

Why can't the hardware provide access to the raw sensor data and let freedom-respecting software deal with it?

It does. https://patchwork.kernel.org/project/linux-media/patch/0d4dc...

You can think of the VideoCore ISP firmware task as a proprietary application and the Pi Camera as a hardware security dongle for that proprietary application.

You can choose not to run that application and access raw data from CSI if you'd like, but if you want to run the special ISP firmware application, you need the hardware dongle.

I think I feel the same way about the DRMed blob as I do about the Pi in general: I understand why the Pi folks did things the way they did, I don't think it's unethical by any stretch, but the situation is disappointing and I would prefer the alternative.

It does. Most people get enraged about RPI cameras unnecessarily. If you don't want to buy cameras from the RPI foundation and want to use/design/connect your own, nobody is stopping you. If you want raw sensor data off the RPI cameras, nobody is stopping you either. It's only when you want to use their image processing with a clone camera that you run into problems.

I just can't get worked up about this, I think this is completely fair.

This is the same argument for closed-source GPU drivers. "Oh, my special secret sauce algorithms!"

Nah. If you want the cred from being open source, be open source.

> then maybe don't call yourself a "charity"

The Raspberry Pi Foundation is a charitable organization registered with the Charity Commission for England and Wales. [0]

We can quibble over whether we think they're doing work in the best way, but by authoritative definitions they are a charity.

[0] https://en.m.wikipedia.org/wiki/Raspberry_Pi_Foundation#Foun...

This is the part where HNers learn that simply being registered as a charity doesn't mean jack shit.

Hospital systems that make billions of dollars a year of profit are charities! Companies that own billions of dollars of real estate holdings for no purpose except speculation are charities!

Non-profit simply means that profits aren't paid out to shareholders. It doesn't mean you can't make enormous profits and accrue vast amounts of wealth.

Notoriously in England, public schools are charities. My school made god knows how much by offering a few bursaries and thereby counting itself as a charity. My best friend's school, old Slough Comp, is possibly one of the greatest forces of anti-charity and anti-egalitarianism in the country and yet is still - IIRC - a charity. It means absolutely zero whatsoever. Perhaps other countries are different.

For people in the US "Public School" in the UK are actually private.

And "Slough Comp" is a tongue in cheek name for Eton College

>"Public School" in the UK are actually private

That's confusing as hell. Can anyone please explain?

Yeah, sure. When they started[0], the aristocracy were educated by private tutors, and these schools actually were for the poor (ok, fine: for 'poor', read 'slightly less than royalty'). That context has obviously changed a lot since, and it now feels a bit silly.

Also, while that person's comment is correct, it's worth noting that not all private schools are referred to as public schools. That name is only for the oldest, mostly-boarding schools that were big players when the system was (finally) formalised in the 19th century. The vast majority of private schools would just be called private schools. And then state schools are the genuinely-free ones.

[0] ETA: Mostly around the Tudor period I believe; i.e. by Shakespeare's time most if not all of them were well established.

Yes -- but also all "Public" schools were not "Church" schools.

Basically there is a time when education was almost exclusively monastic; those who were not taught privately were taught by religious institutions.

The public schools were free of that influence to a greater extent.

There is one more tier of school you don't mention which sits somewhere below "public": the "commercial school". There were some of these owned by the livery companies, and were a tier of schools that were created along the lines of the public schools but before the school system was fully established. Most of them were not fee-paying but were funded by donations or livery company charitable funds. They taught largely vocational skills (but professional ones rather than technical ones); parents sent their kids to commercial schools to bring back the knowledge to professionalise the family business or to set them up in a trade.

(I went to a school that was originally founded this way, but was a part-state-owned grammar school by the time I got there a century later)

Oh wow, thanks for adding that detail. I didn’t know about practically any of that. That’s a fascinating side of things: I thought there must have been a slight lacuna in my understanding, that not all the educated classes could have employed private tutors, and that definitely fills in a missing link for me.

Though it adds another small question: aren’t/weren’t most public schools severely Anglican? I know my school was quite radical at the time for admitting Jewish boys, so that always painted a picture of a not-exactly-super-secular institution, but maybe I’ve got the wrong impression in some way...

Also, those commercial schools sound a bit - subtracting for a moment the fee-paying aspect - like the German technical education system which I’ve always liked the sound of. I wish we had something more like that today, though obviously now it wouldn’t - or shouldn’t - be fee-paying.

> Though it adds another small question: aren’t/weren’t most public schools severely Anglican?

Yes -- implicitly.

(sidebar: I am not sure that, when public schools really first sprang up, it was even possible to educate people of Jewish descent; the situation for Jews in england in particular was deeply complicated by their unique relationship to the state as established by the Magna Carta. Either way, they were not landowners by law and therefore probably not that interesting to the church.)

But at any rate as Wikipedia says, the first public schools appear to have been generalised and detached versions of grammar schools, which were the schools run for wealthy families that were attached to churches and monasteries.

Those schools started off teaching young people the skills needed to function in church life, but eventually they seem to have become so generalised for various other trades that they separated themselves in an administrative sense.

They'd have had lots of clergy doing the teaching nonetheless, I imagine, simply because really only clergy had access to education at that point.

I am not sure how "technical" the school I went to ever was in its earliest form (we did have technical schools in the UK for a while as a precursor to the comprehensive system).

I get the impression it was commercial in the sense that it taught reading and writing necessary for conducting a business, maths necessary for bookkeeping and engineering, and some science.

(The livery company that founded it still owns half of it -- the outside half, literally)

School run by members of the public rather than by the state. So instead of public/private, state/public.

No, it’s really as simple as in my own reply: the American meaning is exactly what the term conveyed when ‘public schools’ began, centuries before today’s ‘state schools’ existed anywhere.

It was a school that was open, in principle, to anyone. Think ‘free as in speech’ vs ‘free as in beer’, but with the added sense - like ‘public transport’ - of being democratic and round-about-accessible to all.

As for the US: when it began, fee-paying schools were the dominant mode, and there wasn’t really an aristocracy with private tutors to distinguish it from. So it never needed the ‘public’ - and when government schooling became a thing, it pretty naturally took on the ‘private’ qualifier instead.

Actually, I think it was that a subset of private fee-paying schools were set up to prepare students for positions in ‘Public Life’ ie politics, military, clergy, civil service - basically running the country aka “The Ruling Classes”.

Nope. Like I said a moment ago[0], it really did just mean ‘free as in speech’, like not-quite-free public transport suggests. Your explanation is certainly very neat and plausible - all the makings of a folk etymology - but it happens not to be correct.

[0] https://news.ycombinator.com/item?id=31008161

You’re right about “Public, as in open to all (who can pay)” being the primary origin of the name, but it has also evolved to mean:

https://www.merriam-webster.com/dictionary/public%20school

“An endowed secondary boarding school in Great Britain offering a classical curriculum and preparation for the universities or public service.”

The purpose of public schools isn’t academic excellence (though of-course they support it for their most able pupils) but networking and the ‘habits of person’ necessary to compete socially in class-sensitive institutions.

Run by -- and for -- the public not by/for the church.

The state did not run schools when these were established. It's much older than that as a term.

Consider also how in the USA, "public" companies are actually private.

Actually, it's worse than that! Fee charging schools can be known as both public and private schools. Those terms are never used in the UK for schools funded by the state. A state funded school will be labelled as Primary, Secondary etc. Some are known as State schools. Some are Academies (a bit more complicated but largely publically funded) etc. Basically in England anyway, Public and Private schools are fee charging schools. The name does not refer to how they are funded.

I went to a private school aged nine to 13 and a public school 13 to 18. Then I went to a polytechnic, which changed its name after a year and then two (three?) years later it was a university! Whilst in sixth form (17/18)

So the message here is that the public/private distinction for school nomenclature here in England and perhaps some or most if not all the UK doesn't mean what it does elsewhere, unless it does except where it doesn't ... except on a weekend when all bets are off. Clear? Jolly good. As you were, carry on!

Thanks for adding that detail! Also for being the one person who replied ITT with a non ’apocryphal’ etymology. I was getting ready to dig into another “public schools are called public because you can see them from the road!” pseudohistory...

And, more importantly, thanks for adding detail on the state school side of things, which I suppose I left out of my answer because it’s not something I know about. It was definitely sorely needed.

In brief, read 'for the public' rather than 'by the public'.

Another example - public houses (aka pubs) are generally for-profit private (or large chains may be public in the sense of being listed) companies that take your money in exchange for real ale and good food; not social housing!

The more confusing thing is that we now (see history in sibling comments) have 'private schools' too. What you call 'public' are 'state' schools here, or something more specific where it's implied ('grammar', 'comprehensive', 'academy').

It doesn't mean 'absolutely zero' - the key point is that it must have charitable aims and objectives which it strives to achieve or encourage.

For example, a university student union can sell you beer in the SU bar and run events to raise cash in order to further its aims in education and student experience etc.

> It means absolutely zero whatsoever

I know you're being dramatic, but at least charities in the UK do have vastly different treatment by HMRC, and much more granular financial reporting requirements.

Raspberry Pi foundation annual accounts are here: https://s3.eu-west-2.amazonaws.com/document-api-images-live....

For example we can see one member of staff was taking home more than £290k in 2020

It seems this is a rather profitable business hiding beneath the label of "education exemption"

A UK registered charity has to have a "public benefit requirement" and has some fierce governance and reporting requirements, it's more than just a non-profit company.

https://www.gov.uk/guidance/public-benefit-rules-for-chariti...

It's the same in the US, but in both cases, "public benefit" is nebulous and unenforceable. If you just say "we're advancing public health!" that's a charitable purpose, even if the majority of what you're doing is profit-seeking and completely unrelated to that.

Much like how CEOs get wide discretion as to what "advancing shareholder interests" means - maybe it's in the long-term interest of public health to build a huge amount of real-estate holdings that you could (hypothetically) use to generate revenue and advance public health (uh huh) some time in the future. That's perfectly fine for a non-profit to do - they really are just a corporation that doesn't pay out profits to shareholders, they keep it all internally.

Examples: the Susan Komen foundation. College endowments. Hospitals. Etc.

In my time at a non-profit, we had what we called our "contribution margin" which was equivalent to profit in a for-profit company, and that was tens of millions of dollars a year. Like I said, we had big real-estate holdings etc which is where all the profit went year-over-year. And we actually did do important public health work, but we were also essentially a contractor for various state and federal agencies and definitely did turn a profit.

The only requirement in the US is that at least 5% of the activity must be charitable in nature - that's not a typo. So spend 5% on some studies and reports and the rest becomes your personal slush fund. It's a fantastic little arrangement.

https://www.ncfp.org/wp-content/uploads/2018/09/The-Five-Per...

Yeah that's not at all the same thing as a UK charity, which has to spend all of its money on charitable purposes.

They are governed by a board of volunteer, unpaid trustees who can be personally liable for its misconduct.

Here's the Raspberry Pi Foundation's entry on the register:

https://register-of-charities.charitycommission.gov.uk/chari...

> a UK charity, which has to spend all of its money on charitable purposes.

No.

> The most popular charities in the UK spend anything between 26.2% and 87.3% of their yearly income on charitable causes, according to the best available data.

https://www.theweek.co.uk/fact-check/98581/fact-check-how-do...

Also that doesn't include accumulation of wealth in general - it's perfectly fine to sock away a billion dollars (or pounds) because in principle that money is going to go to charitable activities in the future. Sometime. But there's no legal requirement that "sometime" ever come, so it's just a slush fund.

Again, please don't think of charities as being charities in the traditional sense of feeding nuns and orphans. It may be better to think of them as "non-shareholder corporations". They are corporations, which make money, and accumulate wealth, which is controlled by the board. The difference is that the purpose of the accumulation of wealth isn't for the benefit of shareholders, but in principle it's for the public. In practice it is a slush fund for the board.

You've got tons of UK universities that build up huge endowments, right? Do you think they're the only ones who do that? And not everybody is using that money for scholarships, as it were...

I know how to think about UK charities, thanks mate, I am trying to offer perspective, experience and knowledge that's different to yours.

I'm a trustee of a small UK charity, I do their books, I'm in touch with lots of other trustees and in no way can these companies be run as a "slush fund for the board". The regulatory regime demands too much transparency for that to happen at any scale.

> The most popular charities in the UK spend anything between 26.2% and 87.3% of their yearly income on charitable causes, according to the best available data. ... > Also that doesn't include accumulation of wealth in general - it's perfectly fine to sock away a billion dollars (or pounds) because in principle that money is going to go to charitable activities in the future. Sometime. But there's no legal requirement that "sometime" ever come, so it's just a slush fund.

Yes, UK charities are allowed to spend on fundraising, investment and may build up reserves. Some of those reserves might be restricted, for specific purposes even within the definition of their charitable purposes, and that needs particular accounting. But that money is absolutely locked up for their registered purposes, it can't go to personal benefits, and their boards of unpaid trustees are on the hook for mismanagement.

If they spent every pound they received on their purposes, lots of charities would cease to exist (or exist 100% on grants from other organisations). That would certainly suit a lot of simple-minded people's perspective on "what a charity should be" but it would shrink the sector to almost nothing.

(I once did data entry for Oxfam, entering direct debit donations posted to the organisation - a few angry people liked to use those appeal envelopes to protest about the fact that Oxfam advertised at all).

Thank you for this.

Part of the problem with the cynical view of charities that you're responding to is that if it goes unchallenged, it actually becomes practically impossible to help charities improve their charitable efficiency.

If people think all charities are BS, they stop donating, and it becomes meaningless to say charity X is doing a better job on a structural level than charity Y, which is for sure important information for donors.

I've worked on some stuff for a social organisation that is now a registered charity, and it is amazing how deep the tendrils of the regulations actually go -- the extent to which things have to be structured to avoid conveying benefits that aren't the objectives of the charity.

(I also applaud you for doing what you do)

There is no "jack shit" about the Raspberry Pi Foundation's charitable status.

It's really not in question.

They've even relatively recently split the business in two (Foundation and Trading Company) to further protect the charitable aims of the Foundation and avoid the ugly Ikea situation.

There is also (in the UK and in the USA as I understand it) a distinction between not-for-profit and charitable status.

In the USA AFAIK most self-declared non-profit organisations follow or are advised to model themselves on the Georgia Nonprofit Corporation code. But not all non-profits are charities (all charities are non-profits, but as you say, it does not mean they don't _make_ profits from time to time; they just don't return them to shareholders).

In the UK we have slightly different non-profit codes like the CIC (Community Interest Company). They are very distinct from charities.

There are two parts of the Raspberry Pi organisation - the Foundation(a charity) and the Trading company(not a charity).

The hardware is developed sold by the non-charitable part, and recently announced that they prioritise orders from industrial customers over private ones. You cannot expect them to act like a charity - they aren't one.

The only reason the charitable foundation is able to exist at all is industrial interest, though? That seems fair.

Can you name a charity which doesn’t cover its costs and manages to keep operating?

The Raspberry Pi Foundation is a charity. It just owns Raspberry Pi Limited which is a tech company. Don't confuse the two. RPL does the hardware and software stuff. RPF is focused purely on education and outreach work, and can do that because RPL provide the money.

If it were just the peripherals...

https://news.ycombinator.com/item?id=31001880

According to Google, the Pi Foundation explicitly does not call itself or the Pi a "open platform". The only hits are from the forum, where people are pointing out that it isn't.

Doesn't this mean the the Pi foundation has an incentive to discourage open firmware, since it will eliminate the enforcement for their DRM?

Not really. The firmware is basically protecting itself - the closed source firmware contains proprietary image processing code (ISP) for the camera which Pi Trading paid for, so it's only supposed be used with the Pi Camera.

A complete open source re-implementation would either not support ISP, or would include a non-proprietary version of the same or similar code, at which point they shouldn't care.

There's also protecting access to the hardware video codecs, in order to account for licensing fees. They might care about that if the MPEG-LA starts being a dick about it.

> Marcan42 dumped the keys from the VideoCore blob

Certainly only the public keys are part of the blob or not? Only the accessories would need the private key embedded to answer the challenge.

It’s HMAC, not PKI, so the key is symmetric. Why it was implemented this way in particular I’m not sure.

https://gist.github.com/marcan/6dde73a9a0c917cd4fc9784a0a73e...

pretty offtopic but i gave up on waiting for Pi to be open for anything more than business. their shady history of pushing microsoft repos (and crypto keys) without my consent in their Raspbian OS was the last straw.

for those who arent amicable with such a 'charitable' definition of open, pine64 has existed for quite some time. the rock platform easily handles my docker workloads.

https://www.pine64.org/rockpro64/

I'd hardly argue that the RK3399 SoC is more "open" than any of the broadcom SoCs. You can't even _see_ the MMIO tables for the RK3399 without an NDA. This isn't different from Broadcom SoCs, but at least the Pi has a large community behind reverse engineering everything. The RK3399 is barely supported by non-Linux distributions (last I checked FreeBSD didn't even boot the A72 core cluster, just the A53s, which leaves a ton of perf on the table) because any work to support it requires either a) blackbox reverse engineering or b) mucking around with the patches vendors (who _do_ have NDA access) have submitted to Linux.

> I'd hardly argue that the RK3399 SoC is more "open" than any of the broadcom SoCs.

What? The gru-kevin chromebook (RK3399) can be booted without using a single binary blob, absolutely everything (even the arm trusted firmware) built from source. I use mine that way.

I've never seen a laptop with a "broadcom SoC" that could make that claim.

I think you've been deluded by a certain fruit pastry vendor's marketing budget.

https://github.com/SolidHal/PrawnOS

I think we're coming at this from two different definitions of "open". There is a very large difference between "blobless Linux compatible" and "open hardware". Have you tried to use any of these SoCs on any OS other than Linux? Good luck lol, because as I said Rockchip has only really upstreamed support for this chip in Linux and has left everyone high and dry.

This is why I specifically called out the issue of MMIO mappings. Seriously, try and scrounge up the addresses for the DMA engines on the RK3399. Or, hell, literally any information whatsoever about the UARTs. The primary place to find any of this is not in public vendor documentation but rather in the device trees Rockchip has submitted to Linux and the various drives different vendors have submitted. Device trees and digging through a pile of barely document C spaghetti is not a suitable replacement for actual documentation.

I am coming at this primarily from the perspective of an OS developer. I am not particularly concerned with blobs and non-free code. I am, however, incredibly frustrated by the fact that I cannot do even very basic things with my hardware without spending hours going spelunking in the Linux kernel because vendors refuse to actually provide public documentation for the products they ship.

There is a subtly annoying trend in the FOSS community to assume that Linux and Linux derivatives are the only operating systems worth caring about. An undocumented chip which ""runs Linux without blobs"", while perfectly great for Linux users, is not some wonderful thing for everyone who doesn't care about Linux. Frankly, I'd much prefer a blob-ful SoC if it meant I could actually do hardware bring up because a sprinkling of non-free components is much better than not supporting an entire platform.

I don't know how you turned a classic ARM vendor problem into an anti Linux rant. If it weren't for the GPL you would just get a binary blob for a proprietary Linux fork and then you would have to reverse engineer the undocumented features from raw machine code.

This isn't a criticism of Linux itself or the GPL, it's a criticism of the fact that both people replying to me and vendors treat Linux as if it's the only operating system worth caring about. Support for Linux is neat but it is not (and cannot) be the definition of open hardware because Linux is not the only things.

>If it weren't for the GPL you would just get a binary blob for a proprietary Linux fork and then you would have to reverse engineer the undocumented features from raw machine code.

Just because they could be doing significantly worse does not mean that they're actually good. Yes, they could do this. It would not be an open hardware platform. They could also upstream software support in such a way that it is a pain in the ass to figure out how the hardware works, which I also contend is not open hardware platform.

And, anyways, it's a rather bold assumption of yours to assume that the drivers actually work as intended lol. I'm sure many in the Linux kernel community would deeply appreciate being able to just write the damn drivers themselves instead of being left with broken and incomplete drivers with little recourse outside of reverse engineering the hardware or begging random vendors to fix it. This is not indicative of open hardware, this is literally just the same problem except now you've blessed the platform as open.

I see your point. I think everyone is getting caught up around the definition of "open," and we have different wants and needs.

I see how it's frustrating to you that people get GPL source and declare "victory" and give up, leaving BSD in the dust. I'm definitely someone who does this, and you made me think about how much nicer it would be if people continued to advocate for documentation instead.

What I want from my "open" hardware is the ability to access the full source code for what is being executed on my device, to ensure there are not unexpected background tasks and to be able to debug issues end to end without having to do as much reverse engineering. So for me, the giant supervisor blob on the Pi is obnoxious - it does random things I don't know about, and I can't look into it to see what's going on.

What you want from "open" hardware is the ability to write driver code under a very specific software license (BSD).

So for my needs, I'll take GPL drivers against hardware all day versus documentation against a black-box HAL. For your needs, maybe the black-box HAL is OK since it lets you run BSD.

Also, "the drivers work as intended" could just as easily be moved to "the blackbox HAL works as intended" and you have the same problem in your "Broadcom is fine because the HAL interface is documented" scenario. If you make a HAL call and it doesn't do what you expect, you're back to RE again anyway.

Anyway, I think we can all agree that full documentation is the ideal state, but sans that ideal state, I'll take GPL source over documentation and a HAL blob, and you'll take the HAL blob and documentation over GPL source. I think everyone wins if we all keep pushing for the ideal state of unencumbered documentation where we can, instead of sitting back when we have one thing or the other!

What's wrong with A or B?

Obviously documentation would be ideal, but I still think an SoC with freely licensed source code available that talks to peripheral devices directly qualifies as much more "open" than one where even "open source" drivers are actually just talking to mailboxes to a HAL running in an RTOS.

I think the challenge with the Broadcom stuff is fundamentally architectural - even with more reverse engineering eyes on the scene, you're working with an SoC that's a big proprietary blob running on an obscure architecture (VPU) which is hosting an ARM Linux box, vs. the Rockchip stuff which is a much more traditional model with memory and register mapped peripherals.

I am also a big Broadcom VideoCore hater (lol), but:

>an SoC with freely licensed source code

Free as in "GPL". The GPL is incompatible with a slew of other licenses and so being dependent on reading the Linux source for how to write drivers for your own OS is an incredibly perilous legal position should you not license your code under the GPL. Real documentation (for talking to blobs or real hardware) almost allows you to license your code however you please and so it is objectively more free.

This, mind you, is not a hypothetical: I am quite literally in this position and have abandoned Rockchip SoCs (despite being all around better tech) because supporting them would possibly violate the project license and the rights of the other contributors. I can, however, support Broadcom SoCs because their documentation is freely available without licensing stipulations despite their non-free blobs. The Rockchip SoCs are free and open only to the extent you either like Linux or can adhere to the GPL, which is frankly a bizarre position to be in when trying to use an SoC.

If the same key could be integrated into video stream, we could have a way to avoid deep fakes?

Is the video manipulated? Calculate the hash/key, and use a public key lookup for RPi to verify.

To avoid hacking of the key, embed every camera with a unique private key.

With a central authority to issue unique "authentic camera keys"? What dystopian nonsense you're suggesting!

Because without such an authority, what's to stop the deepfake source from generating its own unique key? And we're back to square one.

You don't need a centralized authority. Every manufacturer can issue their own keys.

I take a digitally signed photo and tell you "I took the photo with this tamper proof Canon camera, and I can prove it by taking more photos of any subject you ask for and signing them with the same key".

If you worry that I made an authentic-looking counterfeit Canon camera (but you're satisfied I couldn't have extracted the private key from a real one), Canon can confirm that they sold a camera with that key.

But what prevents me from saying I'm a manufacturer of tamper proof gspr cameras, that just happen to generate deepfakes?

Surely there will be enough cheap devices out there that not everyone can be expected to remember the names of venerable manufacturers? I personally have no idea who makes the camera in my phone.

Anyway, the point is moot. The analog hole is still there, you'll just feed the pixels straight from the deep fake generator into the Really Real Tamper Proof Canon's CCD.

One method would be to have a unique key burned into the image sensor by the manufacturer. That key will be in turn used to cryptographically sign the raw signal output from the sensor to verify that the image was indeed generated by that specific sensor.

Now if the image is compressed, this is obviously moot. But for important documentation and the like, it's feasible to store the signed raw signal to confirm that the image was taken by that specific camera. Of course, this depends on the security of the keystore, the trustworthiness of the manufacturer, etc.

> One method would be to have a unique key burned into the image sensor by the manufacturer. That key will be in turn used to cryptographically sign the raw signal output from the sensor to verify that the image was indeed generated by that specific sensor.

This would be horrible for privacy, although somewhat mitigated if the camera program/app discarded the signature by default.

Yeah it would, and ideally it should be possible for the user to choose to include the signature or not in their images. Though I wouldn't be surprised to see this type of tech being the norm in the future, perhaps in a sneaky way like what they did with printers and digital watermarking (https://en.wikipedia.org/wiki/Machine_Identification_Code). We may even see this in other integrated sensors like a MEMS mic with a built-in AD on the silicon.

This isn't doable. Nothing prevents you from gluing or projecting a screen directly into the sensor, after tone mapping the image properly. There is no winning. It wouldn't even be expensive!

Yes, that has been repeatedly pointed out. And yet the industry still did it and your digital cables carrying video aren't going to work properly without the HDCP DRM.

Yeah, but I can get an HDCP-compliant HDMI capture card for 8$ on Aliexpress, so I really don't care and it really doesn't work. You can also buy splitters that happen to disable HDCP.

possible to hardware hack to create a deep fake and simply pass it though the camera CCD to get it be crypto signed.

Or just take-a-picture-of-a-picture. It's possible to do such things much more convincingly than when Trump tweeted out that classified satellite pic in 2019 with a flash visible in the middle of it.

Satellite imagery suffers from sunlight glint that oversaturates the CCD. That isn't a mark of a fake.

Sure, okay. I was just following what I had thought to be the widely accepted narrative on this, eg:

"CNBC reported that Trump was shown the photo during the briefing. A flash visible in the center of the image suggests Trump or someone else took a photo of the original image — which Hanham says might have been the intelligence briefing slide."

https://www.npr.org/2019/09/05/758038714/can-president-trump...

In any case, the point is that with proper staging, you could absolutely take a picture-of-a-picture in a way that would result in the image being marked as genuine and untampered, even accounting for the signing info including a GPS-based time- and position-stamp and including camera details like focal length.

What stops someone from pointing this camera at a really high resolution display showing anything they want? The analog hole goes both ways.

You could even just remove the lens and glue a screen to the sensor.

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