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Confess your love with zero-knowledge

zkcrush.xyz

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Re: Confess your love with zero-knowledge

#111

Post by vintermann »

LeifCarrotson wrote: post #15
Tomte wrote: post #2

This is some strange notion of zero-knowledge. If Bob publishes his link, and I want to know who his crush is, I can simply try all our classmates' names and quickly find out that it's Alice. Those games only make at least a bit of sense when everybody enters their crush and only when matching both get notified. Also brute-forceable, but at least it's quadratic (if you suspect nothing about crushes, which is unrealis…

You'd want to use asymmetric public key cryptography so that Bob could hash his message with Alice's public key, and it could only be decrypted with Alice's private key.

That lets Bob confess semi-deniably to Alice (if Alice is willing to share her private key, she can still show Bob's confession to Carroll and prove that it's authentic). But it still doesn't do any matching; Alice will know about Bob's feelings whether she returns then or not.

Re: Confess your love with zero-knowledge

#112

Post by a-dub »

aarondia wrote: post #46

To stop my friends from using this to guess who my crush is, a fun iteration could be instead of entering the person’s name, you enter the last text you sent, place you met, etc. Something only the two of you would know … and maybe even something romantic :)

that's called salting.

Re: Confess your love with zero-knowledge

#113

Post by mikebenfield »

pessimizer wrote: post #101
mikebenfield wrote: post #72

Earlier quoted context omitted.

> Those games only make at least a bit of sense when everybody enters their crush and only when matching both get notified. Even then, among heterosexuals they will suffer from the same problem as basically every software platform for romance among straight people: the massive asymmetry in interest between men and women. Men would copy and paste virtually every woman they know into the system as a "crush," so they ca…

> Men would copy and paste virtually every woman they know into the system as a "crush," so they can find which if any of their female acquaintances might be interested, and then they would decide who to pursue. Smart men would, who know their place in the world. Any of them are good enough for you, really. Take the one that you like the most out of the ones who like you. Is this a problem? If it weren't asymmetric,…

I don't follow this, either logically or in practice.

Granted I've never dated as a gay man or as a lesbian, but from what I've observed it seems to me a much smoother and more mutual process than straight dating. I've even heard from bi men about how much easier and less stressful it is to date men than women. AFAICT when both parties are on a level playing field, and there's not a massive asymmetry in power, interest, and investment, there's a lot less grief overall.

> edit: I mean, isn't that Bumble?

Bumble is a valiant attempt to fix this issue but it seems to mostly be a failure. An average man may occasionally get a message (which will usually just say "hi"), but the asymmetry in interest is still there, and it's still mostly men's responsibility to do the real initiating.

Re: Confess your love with zero-knowledge

#114

Post by geysersam »

gizmo686 wrote: post #78
LeifCarrotson wrote: post #15

Earlier quoted context omitted.

You'd want to use asymmetric public key cryptography so that Bob could hash his message with Alice's public key, and it could only be decrypted with Alice's private key.

That still lets Alice find out. I don't see a clear way of mapping the concept of a zero knowledge proof to the crush problem. But the best I can come up with is: 1) No one learns that Alice (claims to) have a crush on Bob 2) Unless Bob also claims to have a crush on Alice, in which case. 3) Only Bob learns that Alice has a crush on him. 4) If Bob learns that Alice has a crush on him, Alice learns that Bob has a crus…

Seems to me such a system must make it expensive to claim to have a crush on someone. Otherwise Bob can just claim to have a crush on everyone and will find out who crushes on him.

Re: Confess your love with zero-knowledge

#116

Post by josephcsible »

vintermann wrote: post #96
PascLeRasc wrote: post #88

Earlier quoted context omitted.

This explained zero knowledge so much easier than that parable about the caves, thank you.

But it isn't zero-knowledge. If it was zero-knowledge, you would be able to know what you had the same gift/crush, but it would be impossible to prove to someone else. Mere hashing doesn't do that. For the crush example (This site), your crush could show everyone the link and their name. For that matter, someone could enter the names of everyone you knew in turn, until you were outed.

An actual zero-knowledge way to do that would be the Socialist Millionaires' Protocol.

Re: Confess your love with zero-knowledge

#117

Post by vintermann »

staticassertion wrote: post #7
random314 wrote: post #6

Earlier quoted context omitted.

Or just tell your crush, without sharing URLs with everyone

Easy as an adult. But as a kid I feel like we jumped through soooo many hoops to de-risk telling someone we had a crush on them. I remember those reallllly early games like MASH or even early "compatibility" apps. Very coy.

There's nothing wrong with only wanting to reveal a crush if it's somewhat returned. If it isn't, you're just putting them in an uncomfortable position for no good reason.

Re: Confess your love with zero-knowledge

#118

Post by sangel »

vintermann wrote: post #96
PascLeRasc wrote: post #88

Earlier quoted context omitted.

This explained zero knowledge so much easier than that parable about the caves, thank you.

But it isn't zero-knowledge. If it was zero-knowledge, you would be able to know what you had the same gift/crush, but it would be impossible to prove to someone else. Mere hashing doesn't do that. For the crush example (This site), your crush could show everyone the link and their name. For that matter, someone could enter the names of everyone you knew in turn, until you were outed.

Non interactive zero knowledge allows one proof to be checked by many verifiers. I think folks would still consider that to be a zero knowledge proof no?

That said, yeah this hashing example is not zero knowledge because, among other things, the hash is not hiding.

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