Every time this resurfaces I like to remind people that this is mostly impractical and not how things actually work at the commercial level.
Just because someone can theoretically demonstrate your fingerprint today doesn't mean you have the same fingerprint in a few days. It's that kind of stability that you actually need for consistent matching for advertising or tracking purposes.
90% of commercial fingerprinting services still rely mostly on the IP address. Once you remove the IP address, you're left with a set of configurations that have a very short half life - volume settings, installed fonts, software versions, etc. You can expect a good portion of your audience to degrade within a couple of days. (Whereas a cookie has a life of 2 years - practically though they only survive a few months).
What you actually pay for from third party vendors is a connection made around a more stable data point - a phone number, an email address, a user ID, etc. With one of these data points you can actually track people across multiple devices for as long as you want.
IMO, data brokering is what should be illegal, not the cookie .
The problem with this is the biggest, most important, and sketchiest data brokering services (credit monitoring) are all but entrenched in law at this point.
I don't really know what you expect, people are obviously going to want to know your credit history when they're lending to you. If you can't tell what loans someone has, they could have opened a hundred different accounts and used the money in the casino.
How should credit reports work?
Well, there are multiple approaches, but here's one that worked well for me: when I purchased a home in the country where I now live, and the mortgage lender asked for a credit report from the (high-privacy) country where I lived the longest, what they got was a letter from that country's central bank listing the penalties for requesting that information. Up to and including jail time.
Suddenly the credit report was no longer a prerequisite to the mortgage.
That is rad. Is your high-privacy country friendly to immigrants? Asking for a friend...
But for real. You say you no longer live there, so I'm assuming you left for more opportunities. My wife and I are interested in countries with opportunities for engineers and privacy. Bonus points if there is engineering research opportunities.
Wouldn't this make credit riskier for lenders, reducing access to credit in general and thus making housing less accessible especially to working people?
Not asking polemically, I just have never studied economics and wonder if my intuition here is flawed
I think the actual trade-off is between average acceptable risk at society level.
Some societies prefer huge risks for huge benefits, in those one (might) need a more detailed credit reports because everything is faster, people accept huge risks and the situation can suddenly change.
Some societies prefer more stability. Lower risks, lower surprises. Less opportunities, everything is slower, people can't even take that many risks, simpler histories will do th trick.
From what I notice though, housing seems to be a problem in both types of societies, irrespective on how credits are given, because there are other things involved (regulation, NIMBY, housing used as value, airbnb, geography, etc).
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You are so full of BS it's scary. No credit report is a non-starter at any financial institution that wants to stay in business. They won't be giving you a loan unless they know you are wealthy e.g. own 17 investment properties already. 'High-privacy' countries is code for 'tax-haven', and 'my money in the Cayman Islands' means your bank is about to run afoul of AML and KYC laws if they give you a loan. And this is the whole world: doing business with America means adopting their financial posture i.e. penalties for doing business with money launderers.
You bring your own data to each credit check.
It feels onerous as an idea because bank statements, monthly bills, payslips, will bequests, stock vests and trades, bank robberies*, and investment income each have different ways of being tracked. At least most of these records of individual financial activity come with a PDF these days. It wasn’t that long ago that applying for a loan meant scanning in papers for your lender to review.
Computers are smarter now. Not only can they read documents (or at least match the shapes against shapes they’ve been told are real) but they can also understand the contents too (or at least match the words against ideas they’ve been told are real.)
There may well yet be a future Data Valhalla where individuals hold their life.zip themselves, and upload whatever bits of it are needed to get that Nordstrom store card / car financing / cheeseburger loan without having an intermediate credit agency.
*I feel there’s a kernel of a joke there about a bank robber asking for a receipt with the loot in anticipation of declaring it on their tax return.
I don't see how this works in reality - The issue is that users wouldn't upload negative information (e.g. county court judgements or the bank robbery from your example).
Credit isn't like insurance where these things can be checked later during a claim (which can then be denied) - you need to know the person is a bad-payer before you send them the ten thousand dollar loan as that affects the terms, not afterwards when they default and you can't get your money back.
For CCJs and bank robberies, you'd upload a clean sheet from the government that gives a list of all CCJs and criminal convictions (in the UK we have a system called DBS for criminal records).
Potentially, with loans or other things, some kind of technical solution could work. You could have a personal document that you control, and you give permission for companies to write to the document.
With a loan, for example, if I give you a loan, I can also append to your document that I've loaned you the money; for every payment you make, I write to the log to say you've made a payment. If you stop making payments, I stop writing to the log. This would be cryptographically signed by me, so it can't be forged.
When you want to take out another loan, you can proactively share your document, the bank can see everything written on the log, and make a decision based on that.
Naively, credit is if you can pay, and if you will pay.
For the latter it’s whether you’ve had a judgment against you, which is a matter of public record.
For the former it’s based on how much money you have and what you spend, including on servicing existing debt. Lying about this would be fraud. In that sense, my proposal does indeed open up a new avenue for fraud but I don’t think that’s the same as it being unworkable!
So what. Maybe it is corrosive to society to provide unsecured credit willynilly. Yes, it makes the banks giant amounts of money, but IMHO consumer credit should only be a thing for two classes of assets (that can be repo'd easy-ish) real estate and vehicles.
The Western governments have horribly failed of caring for their people - cost of living are exploding, and at the moment way too many people are papering over that with unsecured credits backed by their data being free to exploit, and everyone else not willing of doing that is increasingly locked out of existence.
The point of the credit agency is to work for the lender?
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…is the title of my sex tape!
How did lending work before nationwide mass surveillance of consumers and reporting on their activities?
It typically required more direct sources of trust. If you were a grocery store, you might let customers you personally knew to be good for it, run up a 'tab' and settle on payday. If you were a bank, you might only lend to rich high-class people. You can find this all around the world today; the US is a standout for credit scoring and for access to credit. When a British person wants to sell their house, it has to happen on the same day that the buyer sells their old house, and the house they're moving into to be sold, and so on in a big same-day daisy-chain, until you hit someone who has enough cash for initial outlay. In Japan, up until very recently, you could expect your boss to need to co-sign your apartment lease (and your landlord to immediately escalate any disagreements to your boss).
> It typically required more direct sources of trust. If you were a grocery store, you might let customers you personally knew to be good for it, run up a 'tab' and settle on payday. If you were a bank, you might only lend to rich high-class people.
You hit the nail on the head with the first statement. It required humans in the loop. It scaled linearly. Local branch managers had relationships with the people in their community, and knew who could and couldn't be trusted.
It was an imperfect system, where a human could be prejudiced against another human, and deny them access to credit.
Sometimes that would get discovered, and the human was held accountable for their actions, or had their actions upheld by a (org-chart-superior) human.
Similar to the imperfect system today, where the models a computer uses could be prejudiced against a human, and deny them access to credit. Dissimilar in that the model or the computer is rarely, if ever, held to account. "Computer says no" is a meme for a reason.
Sounds like a mess! How in that system will people get access to credit for things like buying fast food or books?
Wow credit for fast food! What about toilet paper? The companies producing toilet paper can't just run a "tab" for their good customers
I can't tell if this is sarcasm, or do you honestly consider credit for fast food a good thing. I hesitate because I know that in America people buy everything with credit (or at least a lot), so it's possible some people think like that. But obviously not buying fast food with credit is a good thing?
they shouldn't
Poor people couldn't borrow and middle-class people paid really high interest rates. Credit ratings are pretty much what enabled the expansion of availability to everyone.
Why should they work. We used to think that money lenders were evil.
Yes, and then in the interim we invented having a hundred trillion dollars in GDP. I prefer having access to credit and so does everyone who owns a credit card. If you own a house, you didn't have its cash value when you bought it; neither your car, nor (most likely) your education. In the days of no borrowing, we solved the problem with ramshackle one-room buildings with dirt floors, handcarts, and the one book whose distributors desperately wanted everyone to have it for free.
> Yes, and then in the interim we invented having a hundred trillion dollars in GDP.
And every now and then we have to rescue banks that are too big too fail at the cost of everyone else, because someone dreamed up a way to increase short term profits that involves giving loans to people who will never pay them back.
> neither your car,
Praising a trillion dollar GDP, but can't afford a used car.
> If you own a house, you didn't have its cash value when you bought it; neither your car, nor (most likely) your education
When I grew up I was told to not make debts if not needed. So many older people did indeed save up until they could afford a car or a house. Education was always mostly free where I lived.
Nowadays it seems like ordinary people would need to pay off a house their whole life and thus also need to keep income high enough to keep paying installments. This takes away so much freedom from people as they are trapped in their high paying jobs...
> If you own a house, you didn't have its cash value when you bought it;
> we solved the problem with ramshackle one-room buildings with dirt floors,
there is a fallacy here. People with access to debt bid up the price of an asset, like a house, against other peoples’ similar access to debt. Sans debt access, the solution was not necessarily a small ramshackle house. The fallacy is the belief that the same asset price - whether opulent or ramshackle house, wouldn’t adjust to the reduced level from the bidding environment. The differential cost of construction for a nicer house can be countenanced in the access-to-debt case, but that is second order.
Illustrative straw-man example: Suppose, once one had a parcel of land, that it was trivial to construct one’s ‘starter home’ the ramshackle house if you like. Get one’s family and friends to help build in exchange for future return favors. As one advances in life, rebuild to have something more opulent. The rub is in the parcel itself. Unlike the would-be house, it had no cost built-in, just whatever price the previous owner was willing to accept to release their parcel. That parcel’s (and those around it) price reflects the market’s access to debt, or lack of access to debt. In the market without access to debt, parcel pricing reflects which buyers have accrued more savings vs other buyers. In the market with access to debt, parcel pricing reflects who can access more debt (through the various means we know of today - down payment ability yes, which parallels the non-debt’s savings case, someone co-signing, long term expected future earning potential vs someone retired, the parcel itself put up as collateral, perhaps other non-immobile assets put up as collateral, like the family oxcart).
The point is that there isn’t necessarily a 1:1 coupling between market’s debt vs non-debt access and whether the construction is opulent vs ramshackle.
> I prefer having access to credit and so does everyone who owns a credit card.
A good number of European countries have only half the poverty rates - the dirt floors and carts you're talking about - of the US yet barely use credit cards.
You send them digitally signed statements from other lenders (who are legally required to give them for free with accurate info) or independent rating agencies, they evaluate them and make a decision. They can have their own model or license one from FICO.
That does mean banks can't know if you lie by omission and hide some unpaid bills, but they can raise the evidence requirements to compensate and I think everyone deserves a second chance.
Having someone vouch for you.
It is illegal, if it's PII without explicit consent.
18 months ago Google publicly stated they were going to start using browser fingerprint data to track users, a reversal of their 2019 policy on it because it was considered too invasive.
https://www.malwarebytes.com/blog/news/2025/02/google-now-al...
There's a fingerprint demo on github called JSCreep (https://abrahamjuliot.github.io/creepjs/) that used to keep your fingerprint profile for 90 days and show you how many times you visited. Worked extremely well, and is still around, but no longer uses the API to retain fingerprint data, so you have to track your hash yourself. It would easily track most browsers across changes in IP address. Only Mullvad, Brave, or Tor would not leave an easily tracked fingerprint.
The demo presented in the royfish.dev link is easily foiled by browser extensions that scramble fingerprint data, the presence of which would itself be detected by more sophisticated profilers and used to define the fingerprint. I can refresh the page and get a new hash and adjective-animal name with the same IP. JSCreep sticks firm to the same hash for me, even with a new IP address and some spoofed browser data.
This fingerprint breaks every 2 weeks when Chrome auto updates. Or any other modern browser.
Overall correct, but you're kind of missing some of the cat-and-mouse details for fingerprinting centered around infosec and anti-fraud purposes rather than generic ad-related tracking. That stuff can get way more intense, and is constantly changing based on new techniques developed, countermeasures from cybercriminals, and mitigations from browser developers.
I think the idea here is that the details shouldn't be publicly known. (Or that if they were they would have to invent their details!)
Is there any way to link this data over longer periods of time?
A lot of data can change over days, weeks, but if you can maintain an accurate fingerprint with tinier changes, and granted you have consistent visits from the user, could you just keep up?
Especially if one service is tapped into several websites, and can continually keep up with smaller data changes and distribute that info. Is this possible? In practice anywhere?
I'm thinking that you just need one website where you can associate a given fingerprint to a specific user and then tracking its activity around the web becomes easy.
Let's say I'm logged in a famous search engine, they associate my fingerprint X to my account A. If they then encounter fingerprint X anywhere else, there is a good chance it was me, A, doing it. If the next day I get fingerprint Y, it gets attached to A as well and the tracking information follows it.
Does this make sense?
You mean, like a really popular web service or app that someone would log into every day/week/month...?
Even easier if, additionally, many of the smaller websites were syndicated into a tracking network?
on what basis do you believe this about fonts? my guess would be that the average user doesn’t install or remove fonts often if ever, but it’s only a guess
I don't actually know how much this happens - software versioning is the biggest one. Chrome updates every two weeks, Microsoft updates once a month, your GPU drivers get updated semi regularly, etc. Any one of those would break the fingerprint.
Your IP changes way less often so that combined with everything else would be more than enough to track you through browser version changes. Even a new IP with the exact same everything else would be pretty easy to correlate too. It just depends on how much they're willing to track and companies are often willing to track a lot already, including things like how fast you type, what kind of movements your mouse makes, etc.
Most people probably have completely default fonts, right? Doesn't seem like much of an identifier anyway
Depending on the browser new fonts can be downloaded and installed automatically. I'd bet most people have a lot more than just the default fonts that came with their OS installed.
Automatically installed fonts don't give much of a signal if they are automatically installed on everyone's machines.
A small list of websites that install their custom fonts can cause you to picked out of a crowd even when other things (like your IP) change. The centralization of the internet probably helps a bit here, but I'm guessing that most people go to smaller websites at least occasionally rather than just spending all their time on a handful of social media sites.
Hm, what if each site install its own custom font to intentionally track users across websites?
Hmm. I used to have to do that a lot, but I haven't in a few years now.
Perhaps, but that would also mean the cardinality is lower.
I was thinking about the literal fingerprint sensor a device has. Imagine a "prove youre not a bot" challenge and the finger scanner pulls up. What a nightmare, reminds me when a website asked me if I want to login with windows hello (facescan)
That is different though. That site is just creating a passkey and storing in your keychain (or windows equivalent). Windows hello unlocks the keychain. It can be your face, fingerprint, usb key, 4 digit pin anything. Chrome already uses this. You’re not sending your face to that website nor to microsoft, I hope.
Yes, very much. I just fear we may end up there at some point...
One intereting part about installed fonts is that many enterprise companies buy specific fonts. Then they are rolled out to all their devices, and sometimes at least one of them will have the company name as part of it's name.
> Just because someone can theoretically demonstrate your fingerprint today doesn't mean you have the same fingerprint in a few days.
Indeed. I checked this website a few hours ago and got one fingerprint. Just rechecked and got another.
On the other hand, browsers don't need to share all this data at all. Sure, IP address can't be hidden, but from your example, installed fonts and volume settings? Why should that be shared at all? Sure, for example for a teams meeting, but you'd have to allow the use of microphones or that, youtube for example doesn't need to know how loud you're listening to a video.
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> Every time this resurfaces I like to remind people that this is mostly impractical and not how things actually work at the commercial level.
Sorry, but that's simply not true. It's actually the default way of how people eg track people across installs in app stores ever since they started removing that feature.