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Privacy Pass Authentication for Kagi Search

blog.kagi.com

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Re: Privacy Pass Authentication for Kagi Search

#91

Post by echoangle »

mortar wrote: post #89
echoangle wrote: post #80

Earlier quoted context omitted.

But what would the government compel them to do? If the method is secure, you don’t need to trust the server. And if they backdoor the open source client, people could notice it in an audit.

The method is secure until they change it. Their docs mention that generating a token is not anonymous, but using a token is. Considering they already know who generated it, it could be trivial for them (to change something server side where the validation occurs, if compelled) to link a particular search to a user.

You don’t get the token itself from the server though, you get something so you can make your own token for which the server doesn’t know who created it. So they can do whatever they like on the server, they can’t identify you.

Re: Privacy Pass Authentication for Kagi Search

#92

Post by echoangle »

stebalien wrote: post #86
echoangle wrote: post #72

I don’t really understand how the protocol can ensure that the server can’t identify the client. As far as I understand, the client sends some information A to the server, the server applies some private key X and returns the output B to the client, which then generates tokens C from the output. If the server uses a different X for every user and then when verifying just checks the X of every user to see which one is…

See section 5.5 of the linked paper https://petsymposium.org/popets/2018/popets-2018-0026.php . I'm not sure if/how Kagi implemented this, but the idea is that Kagi's "public" component can be committed to publicly (e.g., in the browser extension itself).

Thanks for looking it up, that makes sense.

Re: Privacy Pass Authentication for Kagi Search

#93

Post by mortar »

echoangle wrote: post #80
mortar wrote: post #77

Earlier quoted context omitted.

Definitely suggesting the method is secure, assuming the company does all the things they’ll say they do, which I also agree they’ll do. I’m just concerned the government can destroy this all, just by compelling them not to, and change a well intentioned method at any moment.

But what would the government compel them to do? If the method is secure, you don’t need to trust the server. And if they backdoor the open source client, people could notice it in an audit.

I think you’re right, perhaps I’ll do some more reading about it - It seems like it all relies on what the extension does, and if this extension is open source someone will notice as you said. Thanks for the clarity!

Re: Privacy Pass Authentication for Kagi Search

#94

Post by phren0logy »

autoexec wrote: post #85
redserk wrote: post #33

Earlier quoted context omitted.

$10 felt a bit steep until I realized there is probably the economies of scale at play here. 1) There is a marginal payment overhead. I'd assume $0.50-0.75, leaving their amount down to $9-ish. 2) It's a fairly niche product with a still-small userbase. ~40k users at ~$9/mo = $360k/mo (I know there's $5/mo users and $25/mo users but I'd assume there are far more $5/mo and $10/mo users than $25/mo users) 3) They have…

As the user of a service things like payment overhead, a small userbase, and dev salaries aren't my problem. My only concern is what I'm getting for what I'm paying. $5 a month for fewer than 10 searches a day is clearly not a good deal. $10 a month might be worth it for some, but an extra $15 a month on top of that for AI results is kind of crazy.

For me, it's also about voting with my wallet. I'm not enthusiastic about invasive ad tech. As it stands, nobody else offers what Kagi offers at any price. If there were an equivalent service for $5/month, I'd give it a look, but there isn't.

Re: Privacy Pass Authentication for Kagi Search

#95

Post by autoexec »

AlotOfReading wrote: post #12

Pretty cool feature. The unstated downside is that any personalization settings like dark mode, translation, and lens settings are still seemingly tied to account login.

Not only that but your searches themselves likely give Kagi more than enough information to identify you as an individual. We saw that nearly 20 years ago when AOL searches were published and people were able to track down specific individuals from their search terms. (https://www.nytimes.com/2006/08/09/technology/09aol.html)

Re: Privacy Pass Authentication for Kagi Search

#96

Post by fvirdia »

voytec wrote: post #58

[deleted by author]

I believe you should currently be able to - create an account under a pseudonymous email address - pay for a plan using a pseudonymous Bitcoin wallet - use your login session to generate Privacy Pass tokens - search with such tokens via the Tor browser on Kagi's .onion domain

Re: Privacy Pass Authentication for Kagi Search

#97

Post by abound »

stebalien wrote: post #86
echoangle wrote: post #72

I don’t really understand how the protocol can ensure that the server can’t identify the client. As far as I understand, the client sends some information A to the server, the server applies some private key X and returns the output B to the client, which then generates tokens C from the output. If the server uses a different X for every user and then when verifying just checks the X of every user to see which one is…

See section 5.5 of the linked paper https://petsymposium.org/popets/2018/popets-2018-0026.php . I'm not sure if/how Kagi implemented this, but the idea is that Kagi's "public" component can be committed to publicly (e.g., in the browser extension itself).

[I implemented this at Kagi]

And you can validate this, if you try to issue a Privacy Pass search without a private token, you'll get a `WWW-Authenticate` header that kicks off the handshake, and that should be the same for all users for a given epoch (month). E.g.

    curl -v -H 'X-Kagi-PrivacyPass-Client: true' 'https://kagi.com/search?q=test'

Re: Privacy Pass Authentication for Kagi Search

#98

Post by sxg »

_fat_santa wrote: post #56
drdaeman wrote: post #28

Neat! It's rare to see that a service you use actually does something that benefits the user rather that itself. An unexpected, but a really pleasant surprise. I wish this extension would integrate better with the browser by automatically understanding the context. That is, if I'm in a "regular" mode it'll use my session, but if I'm in a "private browsing" mode (`browser.extension.inIncognitoContext`) it'll use Priva…

> It's rare to see that a service you use actually does something that benefits the user rather that itself The reason it's become so rare is most companies in this space (heck tons of tech companies period) have used a business model of offering a thing to one group of users and then turning around and selling the results of that thing to another group of users, where the latter group is the one actually driving you…

The other part to this is that the internet accelerates network-effects, which you can further supercharge by making your product as cheap as possible or free to the former group in your example.

It’s hard to make money by charging a lot to a small group of people since now you’re dealing with anti-network effects. Doubling the price of a product will likely more than halve your user base.

Re: Privacy Pass Authentication for Kagi Search

#99

Post by mortar »

alexwebb2 wrote: post #70
mortar wrote: post #65

I’m not insinuating for even a second that Kagi actually do this, but as a general rule, isn’t any privacy claim dubious at the moment given that more and more governments appear to be able to compel companies to identify their users (especially those searching for illegal content) and further forcefully insist they not disclose it? It’s disheartening to think the great progress we’re making in this sector could be u…

I think the idea here is that it literally can't be traced to the user – at no point is there anything passed that would allow Kagi to make the association between the user and the query.

I see this now, thanks for the clarity!

Re: Privacy Pass Authentication for Kagi Search

#100

Post by MostlyStable »

One of the biggest complaints about Kagi from people who have not yet adopted it is their privacy concerns around having to login and have payment information.

I'm not one of the people that has been concerned about that, but I'm curious to what extent this alleviates those concerns among those that have had them.

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