Brussels launched an age checking app. Hackers took 2 minutes to break it (politico.eu)
45 points by axbyte 2 hours ago
Sweepi 2 hours ago
These are the sources cited by the article:
[1] https://xcancel.com/Paul_Reviews/status/2044502938563825820
[2] https://xcancel.com/paul_reviews/status/2044723123287666921
[3] https://csa-scientist-open-letter.org/ageverif-Feb2026
imo: mostly because the Author wants it be a disaster. The App has not launched, they published the source code in order to invite external review. I dont have time to every claim, but e.g. this [see quote below] seems to be blown out of proportions to me - the app fails to delete a temp. image, which results in a selfie being stored indefinitely(?) on the internal disk of your device - if an adversary has access to the internal disk of my phone, they can also just access the photo roll.
"For selfie pictures: Different scenario. These images are written to external storage in lossless PNG format, but they're never deleted. Not a cache... long-term storage. These are protected with DE keys at the Android level, but again, the app makes no attempt to encrypt/protect them.
This is akin to taking a picture of your passport/government ID using the camera app and keeping it just in case. You can encrypt data taken from it until you're blue in the face... leaving the original image on disk is crazy & unnecessary."
JimDabell 2 hours ago
Note that this is an implementation of eIDAS:
The point of this is that you can use the credentials on your phone to prove that you are an adult to a website using zero-knowledge proofs to avoid disclosing your identity to anybody.
If somebody who has access to your unlocked phone can access the data in the app, then this is something that should be tightened up but it’s a substantial privacy improvement over the far more commonplace option of uploading your ID to every website that wants to know if you are an adult.
It’s an attempt to avoid things like this:
> Discord says 70k users may have had their government IDs leaked in breach (Oct 2025, 435 comments) - https://news.ycombinator.com/item?id=45521738
snackbroken an hour ago
> The point of this is that you can use the credentials on your phone to prove that you are an adult to a website using zero-knowledge proofs to avoid disclosing your identity to anybody.
It is my understanding that this is not possible. I would be happy to be shown to be wrong, but to me it seems like you can either prevent people from lending out their credentials, or you can preserve the anonymity of the user, but not both.
You can use 0KP to prove you have a signed certificate issued by your government that says you are an adult, but then anyone with such a certificate can use it to masquerade as however many sock puppets they like and act as a proxy for people who aren't adults. You can have the issuing government in the loop signing one-time tokens to stop Adults-Georg from creating 10k 18+ attestations per day, but then the issuing government and the service providers have a timing side-channel they can use to correlate identities to service users. Is there some other scheme I'm missing that solves this dilemma?
JimDabell a minute ago
> It is my understanding that this is not possible. I would be happy to be shown to be wrong, but to me it seems like you can either prevent people from lending out their credentials, or you can preserve the anonymity of the user, but not both.
This is not designed to prevent adults from coöperating with minors; that makes no sense as a design goal because any technical measure can always be bypassed with “download this for me and give me the file”. This is designed to prevent minors from being able to access systems without an adult.
Nothing prevents an adult from buying alcohol on behalf of minors; that doesn’t mean laws that prevent minors from directly buying alcohol are useless.
actionfromafar 4 minutes ago
Can attestations be rate-limited or is that the timing side-channel you are talking about?
nottorp 20 minutes ago
> The point of this is that you can use the credentials on your phone to prove that you are an adult to a website using zero-knowledge proofs to avoid disclosing your identity to anybody.
That's the theory. How is it in practice?
In my opinion, it just means there is a single government database to hack to get copies of all IDs...
By the way have the "security experts" checking this app evaluated that part? Or they're just worried about the app users cheating?
sofixa 8 minutes ago
> In my opinion, it just means there is a single government database to hack to get copies of all IDs...
That doesn't make sense, all IDs are already in a single government database. Kind of by definition in fact, for IDs to be useful they need to be emitted by a central authority with associated security and revokability guarantees.
The implementations I've seen rely on an app reading your physical ID and its NFC chip, comparing that with a selfie to ensure it's the same person, and being able to provide anonymous proof you are of age based on that, or proof that you are indeed who you say you are.
Mindwipe 14 minutes ago
> The point of this is that you can use the credentials on your phone to prove that you are an adult to a website using zero-knowledge proofs to avoid disclosing your identity to anybody.
No it isn't.
Literally that is not the scope document, and such a solution would not be permitted by the EU as compliant with the legislation.
The app isn't zero knowledge. A prototype workflow has been designed for a one way transfer to sites that is zero knowledge, but it doesn't actually deliver zero knowledge because it you have to verify your age with an external provider to get the credential (which is not zero knowledge), the app has to be secured with either Apple or Google's attestation services (which are not zero knowledge), and the site has to be able to check with the original external provider that the credential hasn't been revoked (which is in no way zero knowledge).
sam_lowry_ 2 hours ago
You are mixing things up, and EU abbreviations do not help.
Many countries in EU already have electronic identity documents and delegate authentication to mobile apps one way or another.
eID or mobile identity application operating over QR codes and used to log into websites and apps is a commodity here.
This has nothing to do with age verification.
JimDabell 6 minutes ago
I’m not sure what you are saying I am mixing up.
The article links to the source code repository here:
https://github.com/eu-digital-identity-wallet/av-app-android...
That links to the tech spec:
> The solution leverages the existing eIDAS infrastructure, including eIDAS nodes and the trust framework for trusted services, to ensure a high level of security and reliability. By aligning with the technical architecture of the EU Digital Identity Wallet ARF, the solution delivers secure, reusable, and interoperable proofs of age.
> The solution enables users to present their Proof of Age attestation to Relying Parties, primarily for online use cases. The system is optimised for secure and privacy-preserving online presentation, allowing users to prove their eligibility without disclosing unnecessary personal information.
— https://github.com/eu-digital-identity-wallet/av-doc-technic...
Annex A includes details on the ZKP:
> AVI SHOULD support the generation of Zero-Knowledge Proofs using the solution detailed in: "Matteo Frigo and abhi shelat, Anonymous credentials from ECDSA, Cryptology ePrint Archive, Paper 2024/2010, 2024, available at https://eprint.iacr.org/2024/2010".
— https://github.com/eu-digital-identity-wallet/av-doc-technic...
And the linked paper:
> Anonymous digital credentials allow a user to prove possession of an attribute that has been asserted by an identity issuer without revealing any extra information about themselves. For example, a user who has received a digital passport credential can prove their “age is ” without revealing any other attributes such as their name or date of birth.
Teafling 2 hours ago
The title of the original article seems wrong, they didn't launch the app, they published the source code ahead of the launch.
mrweasel 2 hours ago
> "Let’s say I downloaded the app, proved that I am over 18, then my nephew can take my phone, unlock my app and use it to prove he is over 18."
While I appreciate the zero-knowledge proofs is considered, how the hell did no one in charge of the app design think of this? It's is literally the first question I asked when I first heard about this app. You go to the app in a store to buy alcohol, you're asked to verify your age, but that's not what you're doing. Your simply showing the store that you have a phone, with and app, which was configured by some over 18 (maybe).
Honestly I don't think it's possible to verify that you're over 18 without also providing something like a photo ID (and even that is error prone).
You can probably do something online, where the website or app does some back channel communication to a server that verifies a token. Even that is going to have issues. You could add a "List of sites that has verified your age" option where you can revoke the verification, in case your nephew borrows your phone.
They are going to implement this and it will be "good enough", but I don't see this being 100% secure or correct.
Sweepi an hour ago
Just like anyone can take anyone's credit card and go shopping - but in contrast Phones are (or at least can be) much more secure.
mrweasel an hour ago
That's not what you're competing with. Your competing with a drivers license with a photo (not a great photo) and some countries have pretty easily faked drivers licenses, but others have drivers licenses in hard plastic with holographic features.
The credit card doesn't work as age verification.
klausa an hour ago
Mashimo an hour ago
How does the nephew unlock the phone and app?
mrweasel an hour ago
If it's just a PIN, and the PIN is his aunts birthday, it might not be much of a challenge. We also have to consider the cases where the adult is complicit, in these cases the app is even less secure than photo ID (for store purchases, not necessarily online).
soco 2 hours ago
"Let’s say I downloaded the app, proved that I am over 18, then my nephew can take my phone, unlock my app and use it to prove he is over 18." - and how is that something that could, or should, be addressed by the app? Are we even serious??
mr_mitm 5 minutes ago
The phone also needs to be rooted for any of the attacks to work.
At least that's what the manufacturer's AI generated article says: https://eidas-pro.com/blog/eu-age-verification-app-hack-expl...
kdheiwns 2 hours ago
Because people share phones with their kids. It's not rare or even mildly unusual. The problem isn't that the app needs to solve this. The problem is the app is useless, along with this whole bizarre "need for age verification" plot that poofed out of existence simultaneously around the whole globe mysteriously a few months ago.
Sweepi an hour ago
Well, reality called and says: Like ID, drivers license, credit cards and guns: Phones are sth. you dont just "share" with your kids. Also there is an option to guard the ID App with an additional PIN/Biometric.
mrweasel an hour ago
kdheiwns an hour ago
JoshTriplett an hour ago
Exactly. "Age verification" is the "think of the children" marketing campaign for "identity verification". Governments don't like anonymity; it makes it harder to find those they consider enemies. But it's hard to market something people don't want and get no benefit from. So, you dress it up in fear and make it easy to villify people who argue against it.
ramon156 30 minutes ago
The Solution: constant face tracking /s
close04 an hour ago
On top of the pretty bad article, HN finds the “can’t win” scenario again. There’s no age verification scheme that will survive “collusion”, that’s when the adult allows the minor to use validated credentials, devices, etc. And whatever more intrusive age verification schemes we come up with will also fail this but add the intrusiveness to ruffle even more HN feathers. We can have the constant face, fingerprint and DNA scan for as long as the sensitive apps is used. Everything gets stored on a central server for safety so your kid can’t hack the device and replace the reference sample. /s
> "Let’s say I downloaded the app, proved that I am over 18, then my nephew can take my phone, unlock my app and use it to prove he is over 18."
Love the magic step in the middle, unlock my app. Ask for passcode or faceid to “unlock your app”. That’s a lot of legwork the adult has to do so the child can “trick” the system.
Some people will forever be shocked that if they leave on the table an open booze or medicine bottle, loaded gun, etc. a child can just take them and misuse them. The blame is unmistakably with bottle and gun manufacturers, right?
Put a modicum of effort to protect the sensitive apps or supervise the child when you share your device. They can do a lot of damage even with age appropriate apps. Wanna see how quickly your kid will tell everyone on the net how much money you have (via proxies), where you live, and when you go on vacation? Or tell someone the credit card number they swiped from your pocket if the other person makes it sound like a game?