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Opening up ‘Zero-Knowledge Proof’ technology

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Re: Opening up ‘Zero-Knowledge Proof’ technology

#51

Post by [deleted] »

MatteoFrigo wrote: post #47
coldpie wrote: post #45

Earlier quoted context omitted.

Thank you. > Your phone stores the document, with cooperation from a secure element that binds the document to the phone. The website you visit verifies the proof. So it does require a "blessed" implementation, and I have to trust Google or Apple to handle my data? I cannot own the document myself and use an open-source client that I trust to provide the proof?

It depends on local regulations. As far as I can tell Europe will require some sort of blessing of the wallet. To be clear, governments will develop their own apps and it's not clear that Google will be blessed. We (Google) are giving them the code pro bono to improve privacy.

[deleted]

Re: Opening up ‘Zero-Knowledge Proof’ technology

#52

Post by MatteoFrigo »

coldpie wrote: post #46
abhv wrote: post #44

Earlier quoted context omitted.

(1) in this case, an identity issuer provides the source of truth identity information. Examples include state DMV, your passport (you can try "Id pass" in Google wallet), etc. (2) One of the goals of this project was to layer ZK on top of current identity standards that DMVs already issue, so that gov orgs don't have to change what they currently do to support the strongest user privacy. One example format is called…

Thanks for the reply. So in theory, I could get this MDOC file and store it on my desktop computer, and use an open-source library whose behavior I can verify, to provide the proof to the website via my web browser. Yeah? This sounds good to me.

No. Using the MDOC requires a signature from a hardware security key in the phone, and a lot of the complexity is how to avoid leaking the private key, which would identify you.

Re: Opening up ‘Zero-Knowledge Proof’ technology

#53

Post by MatteoFrigo »

doctorpangloss wrote: post #49
abhv wrote: post #44

Earlier quoted context omitted.

(1) in this case, an identity issuer provides the source of truth identity information. Examples include state DMV, your passport (you can try "Id pass" in Google wallet), etc. (2) One of the goals of this project was to layer ZK on top of current identity standards that DMVs already issue, so that gov orgs don't have to change what they currently do to support the strongest user privacy. One example format is called…

Are you trying to say that there’s a signed blob called an MDOC, that happens to have the age and name of the user, and this library allows a website to prove that the provided age belongs to the person with the MDOC, but not also see the name?

Yes

Re: Opening up ‘Zero-Knowledge Proof’ technology

#54

Post by add-sub-mul-div »

api wrote: post #8
krunck wrote: post #4

Age assurance will be the gateway to government issued(via corporate proxy) internet usage permits.

True, but I'm also not convinced that a ten year old being able to be face to face with hard-core BDSM and incest fetish porn within 40 seconds of opening a web browser is healthy. I don't like this but don't have another solution other than the porn industry self-policing which isn't promising.

Teen pregnancy rates are down since the mass adoption of the internet, a kid learning a few years early that there exist sexualities other than the default one will affect them much less than losing internet privacy and anonymity for life.

Re: Opening up ‘Zero-Knowledge Proof’ technology

#55

Post by coldpie »

MatteoFrigo wrote: post #47
coldpie wrote: post #45

Earlier quoted context omitted.

Thank you. > Your phone stores the document, with cooperation from a secure element that binds the document to the phone. The website you visit verifies the proof. So it does require a "blessed" implementation, and I have to trust Google or Apple to handle my data? I cannot own the document myself and use an open-source client that I trust to provide the proof?

It depends on local regulations. As far as I can tell Europe will require some sort of blessing of the wallet. To be clear, governments will develop their own apps and it's not clear that Google will be blessed. We (Google) are giving them the code pro bono to improve privacy.

Hmm. This introduces a third party to the protocol, right? Specifically the developer of the wallet. So we now have three parties: the user, the wallet developer, and the relying party. Does this zk protocol protect the user's privacy from the wallet developer as well as the relying party?

In other words, does the protocol give the wallet access to information about the relying party? For example, could this wallet that I don't control tell its owner, or the government, that I am using it to access a certain website?

Re: Opening up ‘Zero-Knowledge Proof’ technology

#56

Post by tptacek »

bobbiechen wrote: post #29

Anyone have a good explanation on the intuition of non-interactive zero-knowledge proofs? For example, I thought the "paint-mixing" analogy for Diffie-Hellman key exchange ( https://en.wikipedia.org/wiki/Diffie–Hellman_key_exchange#Ge... ) really helped me handwave the math into "mixing easy, unmixing hard". https://blog.cryptographyengineering.com/2014/11/27/zero-kno... was a good intro for interactive ZK proofs but…

If you're looking for something at the level of paint cans, I think you want Matthew Green's "crayons and hats":

https://blog.cryptographyengineering.com/2014/11/27/zero-kno...

Re: Opening up ‘Zero-Knowledge Proof’ technology

#57

Post by coldpie »

MatteoFrigo wrote: post #52
coldpie wrote: post #46

Earlier quoted context omitted.

Thanks for the reply. So in theory, I could get this MDOC file and store it on my desktop computer, and use an open-source library whose behavior I can verify, to provide the proof to the website via my web browser. Yeah? This sounds good to me.

No. Using the MDOC requires a signature from a hardware security key in the phone, and a lot of the complexity is how to avoid leaking the private key, which would identify you.

Well, that's not great. My phone is closed-source and its software is provided by an ad company. I do not trust it to always behave in my interests.

Re: Opening up ‘Zero-Knowledge Proof’ technology

#58

Post by kridsdale1 »

jjmarr wrote: post #19
krunck wrote: post #4

Age assurance will be the gateway to government issued(via corporate proxy) internet usage permits.

Not necessary, Uganda has been levying social media taxes on end-users since 2018 by automatically adding it to your cell phone bill if you access a social media website. About 2.7¢ per day of usage.[1] Virtually everyone gets their internet from an ISP that is regulated in the country that the user lives in. There are no technical barriers to implementing a permitting system in the United States. Linking connections…

VPN or TOR?

Re: Opening up ‘Zero-Knowledge Proof’ technology

#59

Post by noman-land »

bobbiechen wrote: post #29

Anyone have a good explanation on the intuition of non-interactive zero-knowledge proofs? For example, I thought the "paint-mixing" analogy for Diffie-Hellman key exchange ( https://en.wikipedia.org/wiki/Diffie–Hellman_key_exchange#Ge... ) really helped me handwave the math into "mixing easy, unmixing hard". https://blog.cryptographyengineering.com/2014/11/27/zero-kno... was a good intro for interactive ZK proofs but…

There's a Where's Waldo explanation that I can't find right now but helped me a lot.

Re: Opening up ‘Zero-Knowledge Proof’ technology

#60

Post by MatteoFrigo »

coldpie wrote: post #55
MatteoFrigo wrote: post #47

Earlier quoted context omitted.

It depends on local regulations. As far as I can tell Europe will require some sort of blessing of the wallet. To be clear, governments will develop their own apps and it's not clear that Google will be blessed. We (Google) are giving them the code pro bono to improve privacy.

Hmm. This introduces a third party to the protocol, right? Specifically the developer of the wallet. So we now have three parties: the user, the wallet developer, and the relying party. Does this zk protocol protect the user's privacy from the wallet developer as well as the relying party? In other words, does the protocol give the wallet access to information about the relying party? For example, could this wallet t…

Yes, a malicious wallet could leak your information. This is why some governments will insist on using only blessed wallets. However, wallet+zk is strictly better than sending the plaintext MDOC to the relying party. There are no solutions in this space, only tradeoffs, and elected representatives have picked one tradeoff.
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