
Why SARS-CoV-2 Bluetooth contact tracing apps are a tremendously stupid idea - bluegopher
https://raccoon.onyxbits.de/blog/covid-19-bluetooth-contact-tracing-stupid-idea/
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adrianmonk
> _Bluetooth contact tracing is hyped as a silver bullet, an alternative to
> social distancing._

What a ridiculous straw man argument. Nobody is saying this is a silver
bullet. Nobody is saying it replaces social distancing. That's either
disingenuous or it's based on a massive misunderstanding of the purpose here.

It is one weapon in an arsenal of several, and the goal is to keep using all
of them at once because each one helps reduce R0. Contact tracing doesn't
replace everything else. You keep doing as much social distancing as you can.
You keep washing your hands. And you also do contact tracing.

> _Day 6 [ ... ] Joe’s test results are back: positive. [ ... ] Potentially a
> few hundred people are going to have a really rotten day._

Yeah, well, that _is_ the idea, isn't it? They were possibly exposed.
Sometimes learning bad news means you have a bad day. What's the alternative,
ignorance is bliss? You might also have a bad day if you get COVID-19 and give
it to your grandmother and then she and half the people in her retirement home
die.

~~~
senectus1
Thank you. the "anti tracing app" crowd seems to be split into two teams, one
"Gov are going to use this to abuse and control you" or "it wont stop you
getting the virus, it wont protect you from getting it"

this is NEVER the plan. why cant people get over that fact? Like home made
masks, they're a small layer that helps to reduce the rapid spread. slow it
down, let us control it a bit more.

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andor
_" Ask a computer scientist for their opinion and the answer is: FUCK NO!"_

Of course, because all computer scientists share the same opinion... not!

Some computer scientists are even aware of the limits of their knowledge and
understanding and give answers like "it depends". There are tons of variables
that play into how well any of these solutions work, and yes, there's a
privacy trade-off. Just like with license plates, card payments, mobile phones
and leaving your house. Or using Linux. Are you one of the 10 people using
Linux on the Internet? Yeah, we know who you are ;-) Welcome to the real
world, where people make compromises.

Also: do you really want to be the guy saying something doesn't work while
others are currently _trying to make it work_?

~~~
LargoLasskhyfv
You mean like really tamper proof electronic voting(in practice, under real
world constraints of yadda yarr yarr yadda)?

~~~
pinusc
The comment above lists many solutions that require compromises to work.

We can make compromises on a covid-tracking app. Worst case scenario: fewer
people install it and it's less effective—still better than not having it in
the first place.

We can't make compromises on a voting system—worst case scenario: democracy is
overthrown forever.

There is a BIG difference in the threat models here. The prople objecting to
electronic voting recognize that a major breakthrough in computing security is
needed before we get there. OTOH we van probably design a _reasonable_ covid
app with acceptable compromises.

If you think that having your position tracker is unacceptable: great for you,
stand up for your rights. Most people do have google maps and its tracking
installed, and don't give a crap _because it lets them see traffic_. I think
the tradeoff here is definitely better.

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cameldrv
Obviously there will be false positives and false negatives with this app. If
you could catch even 50% of cases though it would go a long ways towards
stopping spread. The question is whether you can get that without a huge false
positive rate. My guess is that you can, since it appears that the primary
transmission mechanism is sustained indoor contact, within about 15 feet. You
could probably increase the accuracy if you could detect being indoors.

On the cost issue, the obvious solution is to make testing free and easy, and
to provide a financial incentive to get tested quickly after the app alerts
them.

~~~
dustball156
> The question is whether you can get that without a huge false positive rate.
> My guess is that you can

No, you can't. The virus spreads exponentially and the app is suppose to keep
up. In other words, you get an exponential number of alarms.

> On the cost issue, the obvious solution is to make testing free and easy

Cost is not the limiting factor. Equipment, reagents and time is. We could
have easily beaten the pandemic by now if simply going from door to door and
taking a smear test was an option.

~~~
ilogik
the whole point of the app is to isolate people that have been in contact with
positive cases before they become contagious.

if everyone has the app, you won't have an exponential growth.

[https://www.youtube.com/watch?v=gxAaO2rsdIs](https://www.youtube.com/watch?v=gxAaO2rsdIs)

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underyx
I think the author might be under the false impression that coming in contact
with a known positive has some repercussions for you. In reality, it's just an
indication that you should get tested.

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falcolas
> government agencies and law enforcement … to be honest, I have no idea why
> they should be interested, but surely, they will.

This one’s easy. Bob commits a crime. Police think there’s an accomplice. So,
they use a contract tracing system to identify and start investigating Bob’s
direct and second-order “contacts”.

Note - this is independent of the actual implementation, which does seem
fairly secure against such uses. Still, I worry that given the public nature
of the “infected” list, and that phones automatically add themselves to the
list, there are some statistic correlations which could be made.

~~~
ilogik
law enforcement already has location from cell tower data.

to be able to read the ids from contact tracing apps, they need to capture the
phones and decrypt them, at which point there's probably more evidence to be
found than some random ids

~~~
dustball156
Actually no and no.

Having been in the same cell (potentially several square miles) as the murder
victim is not quite the same as having been in tracing distance (4m²).

That's quite a strong argument/pretense, why law enforcement would immediately
lobby to get the system changed in their favor. Don't you agree?

~~~
ilogik
if you use an android phone, check this URL:
[https://www.google.com/maps/timeline](https://www.google.com/maps/timeline)

that information is a lot more sensitive and a lot more useful to law
enforcement. most people don't even know how much your location is being
tracked.

the contact tracing framework by comparison, isn't really very useful for
anything other that just that...contact tracing

------
RandomInteger4
Contact tracing apps sounds like a totalitarian wet dream.

------
ilogik
A couple of concepts that I think the OP has wrong. I'm only talking about the
Apple-Google contact tracing framework:

* you need a key from a doctor to be able to mark yourself as positive.

* when you get a notification that you came into contact with someone positive, that's it....nothing else happens. it's up to you to go get tested (possibly with a priority because of the app)

* you are giving up 0% privacy by using contact tracing

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ilogik
the author doesn't seem to understand how to system works. yes, it's not
perfect, it doesn't tell you you've got it for sure, just to get tested, in
case you've been near someone who has it.

Also, people can't troll using the app, you'll need a key to be able to mark
yourself as infected

~~~
dvt
The article is pretty good and the author seems to understand how the app
works, can you provide some specifics?

I think giving up a significant amount of privacy for technology that’s “not
perfect” is a pretty dangerous slippery slope.

~~~
ilogik
you are giving up 0 privacy. no tech is perfect, but this is very well thought
out.

i've gone into detail here:
[https://news.ycombinator.com/item?id=23053624](https://news.ycombinator.com/item?id=23053624)

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lazylizard
It will help the legions of people employed to do contact tracing manually
right now in places like taiwan korea and singapore..

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drummer
And "fuck no!" is indeed the right answer.

~~~
ilogik
why?

~~~
drummer
The reason is explained in the article where the quote comes from.

~~~
ilogik
none of the reasons make sense sorry about the formating, but i've tried to
cover all of them:

Joe the hacker What if Joe stayed home the first day (did not get infected),
got hold of Jane’s phone and decides to swat her for fun?

// What does that have to do with anything?

Joe, the slacker What if Joe was not a neighbor of Jane, but one of her
students, desperate to meet a deadline. Could he buy himself an extension by
faking an infection?

// not really sure what this has to do with the tracing app...you can't fake
an infection on the app, you have to get tested

Joe, the movie buff What if Joe had invited Suzie to the movies and turned his
phone off before entering the cinema hall?

// who the fuck turns off their phone in a movie theatre?

Joe, the deceived Plot twist: Joe just caught the flu. Same symptons,
different pathogen. Should he wait for test results (or be tested at all)
before hitting the alarm?

// Again, you can only tell your app that you are infected with a key that you
get after you test positive.

Joe, the unprepared Joe is single. What if he runs out of food while
quarantined? Will he sneak out, leaving his phone at home?

// not sure why he's leaving his phone at home? who does that? even if it does
happen, it will be rare.

Joe, the kindergarten teacher What if someone had the idea to reopen
kindergarten, thinking the availability of Bluetooth contact tracing renders
social distancing unnecessary?

// people want to open kindergartens because 'MERICA...not sure how this app
will change things

Jane, the hypochondriac What if Jane had an unrelated symptom, quarantined
herself without a test and thinks, she gained immunity afterwards.

// what does this have to do with the contact tracing app?

Jane, the gym instructor How many contacts would Jane’s phone log, if she left
it in the locker room?

// I don't think most people leave their phones in the locker room. Even if
they do, they will have contacts...other people that are in the gym at the
same time.

John, the secret agent Are there countries that would benefit from keeping
other countries in lockdown? If so, what could be more effective than
interlinking as many people as possible, then sending a fake alarm?

// ugh...sure...I guess...if they're bored? and they get a key from a doctor

101010, the software bug Is it possible that a piece of software, especially
one, that is based on a bad idea and coded in a hurry, might malfunction?

// pretty much everything around us runs on software...yes, there might be
bugs, they get fixed

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dzhiurgis
If you have bars open then there's no point of doing anything to stop spread.

Just focus on inventing vaccine for couple hours a day then hit the pub.

