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TracePrivately – open-source sample app using Apple's contact tracing framework

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Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#21

Post by floatingatoll »

devit wrote: post #13

I don't quite understand why Apple and Google are releasing an API instead of a single system application. This is going to create a gigantic mess as governments with limited software development competence slowly release incompatible and partially broken applications, while Apple and Google could just deploy a single solution via a system update. Also, it's much easier to make it mandatory if it's a system app (and…

What you describe is how iOS was first released. Anyone who wanted to build an app would use progressive web apps. Every native app was controlled by Apple only. This was loathed by developers and corrected in a later release.

Given the steady recurring posts here on HN and elsewhere about hoping that Apple will open up to third-party app selections for email/browser/etc. someday, suggesting that Apple control the only Covid app on their platform is contradictory to that goal.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#22

Post by odensc »

emptybits wrote: post #10
conroy wrote: post #3

Earlier quoted context omitted.

My understanding is that to mark yourself as Covid+, you’ll need a code from a health care provider. I agree that allowing self diagnosis would ruin the entire system.

A quick scan of the linked project suggests no such healthcare provider code is required. The source[1] suggests the flow is literally: "I Have COVID-19" -> "Are You Sure?" -> "Click OK", and that's that. Anyways, I take this project to be a proof of concept. One would hope that governments will have healthcare professionals replacing the self-diagnosis step. * hope * [1] https://github.com/CrunchyBagel/TracePrivatel…

> A quick scan of the linked project suggests no such healthcare provider code is required.

That's why this is a sample app and not the actual application that public health authorities will be using.

See below:

"A representative from Apple and Google's joint contact-tracing project said that their system similarly envisions that patients can't declare themselves infected without the help of a health care professional, who would likely confirm with a QR code." [1]

[1]: https://www.wired.com/story/apple-google-contact-tracing-str...

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#23

Post by yegle »

devit wrote: post #13

I don't quite understand why Apple and Google are releasing an API instead of a single system application. This is going to create a gigantic mess as governments with limited software development competence slowly release incompatible and partially broken applications, while Apple and Google could just deploy a single solution via a system update. Also, it's much easier to make it mandatory if it's a system app (and…

The system is intended to be annonymous and can't have any user registration or authentication.

How can you validate when someone report they are infectious, the Diagnostic Key is indeed from a legit iOS device? If you can't validate it, this can be easily abused (attacker generate a huge list of Diagnosis Keys and upload, claiming to be infected, and causing a wave of public panic)

My understanding is that there must be some internal/proprietary API from Apple that they are using to validate this, and there's no other vendor except Apple to develop such an API to mitigate the abuse risk.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#24

Post by pmiller2 »

yegle wrote: post #20
pmiller2 wrote: post #18

Earlier quoted context omitted.

That sounds like a massive privacy violation to me.

The only time your keys are uploaded, is when you are infected. The assumption is that if you are infectious certain privacy needs to forgo to protect others. In fact this is over simplification. The only key that will be uploaded is partial of the daily tracing key (called Diagnosis Key in the specification). Most importantly, there's no location or timestamp involved or needed. Once this Diagnosis Key is uploaded,…

Right, and there’s no possible abuses this could be used for, of course — no way this data can ever be deanonymized, right? What I object to is putting this all into an automated system for everyone, infected or not. If there’s a way to generate a diagnosis key, there’s a way to spoof it, and that can be used to infer contacts for the non infected.

You may have a point when it comes to the infected, but even then, giving Apple or Google this type of information is putting far too much trust and power into too few hands.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#25

Post by yegle »

emptybits wrote: post #10
conroy wrote: post #3

Earlier quoted context omitted.

My understanding is that to mark yourself as Covid+, you’ll need a code from a health care provider. I agree that allowing self diagnosis would ruin the entire system.

A quick scan of the linked project suggests no such healthcare provider code is required. The source[1] suggests the flow is literally: "I Have COVID-19" -> "Are You Sure?" -> "Click OK", and that's that. Anyways, I take this project to be a proof of concept. One would hope that governments will have healthcare professionals replacing the self-diagnosis step. * hope * [1] https://github.com/CrunchyBagel/TracePrivatel…

If the Rolling Proximity Key is not recorded by other users (e.g. the abuser haven't put their device in a high human traffic location and intentionally broadcast your RPK), attacker uploading Diagnosis Keys will not cause any effect.

If the abuser took the effort to place a device and broadcast RPK for a while, then upload the Diagnosis Keys, I'm hoping Apple or Google have a way to validate the requests is from a legit device and thus abuser would have to have a lot of devices to game the system.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#26

Post by yegle »

pmiller2 wrote: post #24
yegle wrote: post #20

Earlier quoted context omitted.

The only time your keys are uploaded, is when you are infected. The assumption is that if you are infectious certain privacy needs to forgo to protect others. In fact this is over simplification. The only key that will be uploaded is partial of the daily tracing key (called Diagnosis Key in the specification). Most importantly, there's no location or timestamp involved or needed. Once this Diagnosis Key is uploaded,…

Right, and there’s no possible abuses this could be used for, of course — no way this data can ever be deanonymized, right? What I object to is putting this all into an automated system for everyone, infected or not. If there’s a way to generate a diagnosis key, there’s a way to spoof it, and that can be used to infer contacts for the non infected. You may have a point when it comes to the infected, but even then, gi…

Wait what part of the data do you want to deanonymize?

It's computational impossible to reverse from Rolling Proximity Key to Daily Tracing Key to Tracing Key.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#27

Post by Reelin »

yegle wrote: post #23
devit wrote: post #13

I don't quite understand why Apple and Google are releasing an API instead of a single system application. This is going to create a gigantic mess as governments with limited software development competence slowly release incompatible and partially broken applications, while Apple and Google could just deploy a single solution via a system update. Also, it's much easier to make it mandatory if it's a system app (and…

The system is intended to be annonymous and can't have any user registration or authentication. How can you validate when someone report they are infectious, the Diagnostic Key is indeed from a legit iOS device? If you can't validate it, this can be easily abused (attacker generate a huge list of Diagnosis Keys and upload, claiming to be infected, and causing a wave of public panic) My understanding is that there mus…

This is misguided. As you note, the system is anonymous and can't have any registration or authentication. Moreover, an Apple or Google specific API for validation would prevent interoperability of other (future) implementations including any free and open source (ie actually verifiable) ones.

Therefore, all authentication must be done on the receiving end by deciding which data sources to trust. This should be fairly straightforward because when a healthcare provider performs testing they are in a position to collect any keys from you at the same time. They are then the ones trusted to accurately report keys, which should be fine since we already trust them both to accurately report test results and to safeguard patient privacy.

Importantly, such a decentralized design allows for cooperative framework implementations, competing app implementations, and multiple data sources. Google or Apple could run a data server, your local government could run a data server, etc. Even more interestingly, such a framework could be repurposed for other less critical uses later as a form of privacy-preserving mutually opt-in contact discovery. Non-essential use of the framework might even ensure that people keep it running all the time, so that the data is ready and waiting the next time a novel pathogen appears.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#28

Post by Reelin »

emptybits wrote: post #10
conroy wrote: post #3

Earlier quoted context omitted.

My understanding is that to mark yourself as Covid+, you’ll need a code from a health care provider. I agree that allowing self diagnosis would ruin the entire system.

A quick scan of the linked project suggests no such healthcare provider code is required. The source[1] suggests the flow is literally: "I Have COVID-19" -> "Are You Sure?" -> "Click OK", and that's that. Anyways, I take this project to be a proof of concept. One would hope that governments will have healthcare professionals replacing the self-diagnosis step. * hope * [1] https://github.com/CrunchyBagel/TracePrivatel…

Sure, you can report any arbitrary key as positive. I can even do it right here on HN; my positive key that I just made up is "0d d8 cb 25 8a 88 aa df 6a 33 17 5f 59 ad fd bf"!

... now what? Someone has to aggregate that key (along with all the other flagged ones) somewhere, and then end users have to voluntarily choose to download the keys from that source and check for themselves if they came into contact with it. So you would have to get someone to accept your self reported positive key, and then convince a bunch of end users to trust that (apparently untrustworthy) data source.

I expect that most databases will require some sort of authentication from a healthcare provider or known laboratory before they will accept a key from an end user.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#29

Post by sneak »

devit wrote: post #13

I don't quite understand why Apple and Google are releasing an API instead of a single system application. This is going to create a gigantic mess as governments with limited software development competence slowly release incompatible and partially broken applications, while Apple and Google could just deploy a single solution via a system update. Also, it's much easier to make it mandatory if it's a system app (and…

> and obviously it needs to be mandatory to be useful

That's not only not-obvious, I don't even believe it's true. Contact tracing is useful even if only 50% of the population uses such a system. (Remember, not everyone even has a smartphone.)

It would be business suicide to force such a choice on users. I'd throw my iPhone into the nearest river if a system update forced it upon me, even if I trust the system and would have opted in.

Re: TracePrivately – open-source sample app using Apple's contact tracing framework

#30

Post by yegle »

Reelin wrote: post #27
yegle wrote: post #23

Earlier quoted context omitted.

The system is intended to be annonymous and can't have any user registration or authentication. How can you validate when someone report they are infectious, the Diagnostic Key is indeed from a legit iOS device? If you can't validate it, this can be easily abused (attacker generate a huge list of Diagnosis Keys and upload, claiming to be infected, and causing a wave of public panic) My understanding is that there mus…

This is misguided. As you note, the system is anonymous and can't have any registration or authentication. Moreover, an Apple or Google specific API for validation would prevent interoperability of other (future) implementations including any free and open source (ie actually verifiable) ones. Therefore, all authentication must be done on the receiving end by deciding which data sources to trust. This should be fairl…

What you describe is not in conflict with the Apple/Google proposed solutions. Or rather, it (the part of reporting and aggregating on the server side) is not part of the proposed solution.

When tested positive, to which server the diagnosis keys are reported to can vary depending on the platform and app. It could be reported via a goverment approved app, or reported to Google/Apple provided server. As long as Google/Apple aggregate the diagnosis keys across multiple servers (or even multiple servers across multiple countries), we still take the full advantage of this contact tracing framework.

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