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What is Differential Privacy?

blog.cryptographyengineering.com

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Re: What is Differential Privacy?

#11

Post by quantumtremor »

tjl wrote: post #6
applester wrote: post #4

Earlier quoted context omitted.

To paint another viewpoint, Apple initially went all gung ho about privacy and wanted to make not collecting data a big play (and fairly so, full respect to them). The recent WWDC obviously shows a big shift towards AI and ML applications within the company. Some things are possible on the device, but many neural nets just cannot be served from an iPhone reasonably. Hence, the move towards more data collection. I rea…

They talked a bit more about differential privacy in the State of the Union. Basically, they hash the data and add noise. By collecting data from a bunch of people that noise gets averaged out. They also limit the amount of samples (over a relatively short period of time) they can get from a single person so they won't be able to identify them.

At some point, regardless of adding noise, you're definitely losing your privacy. I'd be happy with an "opt-out" feature that I know worked (as far as I can see, only if it was open-source). I didn't watch WWDC, perhaps they mentioned this.

Re: What is Differential Privacy?

#12

Post by johncolanduoni »

quantumtremor wrote: post #11
tjl wrote: post #6

Earlier quoted context omitted.

They talked a bit more about differential privacy in the State of the Union. Basically, they hash the data and add noise. By collecting data from a bunch of people that noise gets averaged out. They also limit the amount of samples (over a relatively short period of time) they can get from a single person so they won't be able to identify them.

At some point, regardless of adding noise, you're definitely losing your privacy. I'd be happy with an "opt-out" feature that I know worked (as far as I can see, only if it was open-source). I didn't watch WWDC, perhaps they mentioned this.

I agree opt-out is definitely something that should be deployed alongside differential privacy, but what makes you so sure that it doesn't work "at some point"? If the noise means an specific query to one user's information has a significant chance of being wrong, how does this not equate to privacy? You can add a lot more noise than you might imagine if you know the kind of analysis you'll be doing with the data; for example, a lot of statistical techniques are constructed to be mostly immune to Gaussian noise since it's very common with some kinds of data.

Re: What is Differential Privacy?

#13

Post by lalos »

hfsbtnye wrote: post #2

I have to admit, I'm really starting to like the direction that Apple is heading despite being previously disenchanted. I only wish that they would go ahead and put everything under a free software license, since they're in the business of selling hardware that's coincidentally bundled with their software.

They know it's one of the ways to differentiate from the other big companies, by offering privacy and marketing in such a way that it's impossible for the other big players to do the classic "me too" approach.

Re: What is Differential Privacy?

#14

Post by bo1024 »

I've read a couple articles and haven't seen any details about how they're going to apply DP (differential privacy).

It's important to clearly distinguish what DP can and cannot do. DP is just a technique for taking a database and outputting some statistic or fact about it. The output has some noise added to it.

The guarantee of DP is (roughly) that anyone looking at the output alone won't learn much about anyone in the database. This also holds for anything you do with that statistic.

Think about this carefully when thinking about what DP does and doesn't promise. Also think about the difference between "privacy" and "security".

Example of what DP does protect against: If Apple is recommending products to people based on others' download habits, and this recommendation is based on differentially private statistics, then no other user or group of users can infer anything about my downloads. In fact, even engineers at Apple, if they can only see the statistics and not the original database, cannot infer anything about my downloads.

Example of what DP does not protect against: government accessing the data. The database still has to exist on Apple's servers. The government can get to it just as easily as before via warrants or so on. DP is not cryptography.

My assessment: On one hand it is awesome that Apple is taking a lead in using differential privacy and thinking about mathematical approaches to privacy. On the other, there are many facets of privacy and right now I think people are more concerned about security of their data and privacy from the government, or else privacy from companies like Apple itself. DP doesn't address these; it only addresses the case where Apple has a bunch of data and wants the algorithms it runs not to leak much info about that data to the world at large.

Re: What is Differential Privacy?

#15

Post by kordless »

It's time for an Open Communications initiative. Time for companies to stop owning the platform. Time for all of us to stand up for our right to communicate with who we want, when we want, without being monitored, inspected, blamed, or advertised to. Enough is enough. It's time for a change.

Re: What is Differential Privacy?

#16

Post by hfsbtnye »

forgotpwtomain wrote: post #7
hfsbtnye wrote: post #2

I have to admit, I'm really starting to like the direction that Apple is heading despite being previously disenchanted. I only wish that they would go ahead and put everything under a free software license, since they're in the business of selling hardware that's coincidentally bundled with their software.

> I only wish that they would go ahead and put everything under a free software license, since they're in the business of selling hardware that's coincidentally bundled with their software. That's never going to happen. Apple sells a 'User Experience' not just hardware - having a complete and mostly closed product is an inevitable consequence of the former - and the number of Linux users that would buy a Macbook isn'…

In what way does changing the software license impede user experience? No other company would have the proverbial balls to straight up copy their software either.

Re: What is Differential Privacy?

#17

Post by kordless »

hfsbtnye wrote: post #2

I have to admit, I'm really starting to like the direction that Apple is heading despite being previously disenchanted. I only wish that they would go ahead and put everything under a free software license, since they're in the business of selling hardware that's coincidentally bundled with their software.

Fuck Apple. The only thing they are programmed to care about is the bottom line and getting more users. That programming is complicated and unlikely to change to suit the consumer's needs, or desires.

Re: What is Differential Privacy?

#18

Post by frankmcsherry »

bo1024 wrote: post #14

I've read a couple articles and haven't seen any details about how they're going to apply DP (differential privacy). It's important to clearly distinguish what DP can and cannot do. DP is just a technique for taking a database and outputting some statistic or fact about it. The output has some noise added to it. The guarantee of DP is (roughly) that anyone looking at the output alone won't learn much about anyone in…

> The database still has to exist on Apple's servers.

It doesn't, which is part of the reason Apple wants to do this. You can still do differential privacy without collecting all the data, you just get less accurate results. See page 232 in [1], re "The Local Model".

[1]: http://www.cis.upenn.edu/~aaroth/Papers/privacybook.pdf

Edit: the article even says this down when it talks about RAPPOR.

Re: What is Differential Privacy?

#19

Post by liquidise »

kordless wrote: post #17
hfsbtnye wrote: post #2

I have to admit, I'm really starting to like the direction that Apple is heading despite being previously disenchanted. I only wish that they would go ahead and put everything under a free software license, since they're in the business of selling hardware that's coincidentally bundled with their software.

Fuck Apple. The only thing they are programmed to care about is the bottom line and getting more users. That programming is complicated and unlikely to change to suit the consumer's needs, or desires.

You say that despite this privacy push being a direct response to consumer sentiments. Apple knows well that as tech becomes wearables and the Internet of things, privacy concerns skyrocket. My grandparents won't buy things online. Soon my generation will be those old and anxious curmudgeons unless our concerns are eased.

Do they care about their bottom line? Of course. It's for that very reason they are investing the time now to secure the trust of generations of consumers.

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