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Show HN: Anonymous Age Verification

(gist.github.com)
70 points jwally | 1 comments | 31 Aug 25 17:14 UTC | HN request time: 0.199s | source

So I'm not an expert in this area, but here's an attempt at cost effective, anonymous, age verification flow that probably covers ~70% of use cases in the United States.

The basic premise is to leverage your bank (who already has had to perform KYC on you to open an account) to attest to your age for age-restricted merchant sites (pornhub, gambling, etc) without sharing any more information than necessary.

Flow works like this:

1) You go to gambling.com

2) They request you to verify your age

3) You choose "Bank Verification"

4) You trigger a WebAuthn Credential Creation flow

5) gambling.com gives you a string to copy

-------------

6) You log into your bank

7) You go to bank.com/age-verify

8) You paste in the string you were given

9) The bank verifies it/you and creates a signed payload with your age-claims (over_18: true, over_21: false)

10) You copy this and go back to gambling.com

---------------

11) You paste the string back into gambling.com

12) You perform WebAuthn Auth flow

13) gambling.com verifies everything (signatures, webauthn, etc)

14) gambling.com sets a session-cookie and _STRONGLY_ encourages you to create an account (with a pass key). This will prevent you from having to verify your age every time you visit gambling.com

The mechanics might feel off, but it feels like this in the neighborhood of a way to perform anonymous age verification.

This is virtually free, and requires extremely light infra. Banks can be incentivized with small payments, or offer it because everyone else does and don't want to get left behind.

1. lyu07282 ◴[31 Aug 25 20:42 UTC] No.45086882[source]▶
Right we still pretend this is about protecting children I forgot.

The proper-ish solution to the problem are zero knowledge proofs: I get my government or whoever to give me a credential with my date of birth, I go to website which asks me for my age, the website gives me a token, I use the token and my gov credential to generate a proof that says "today i'm over 18" i give proof to website, the website verifies the proof using my governments public key and lets me pass. This way nobody knows anything more than necessary and it protects everybodys privacy. [1]

Hey we make it a standard open protocol! So everybody can implement it easily. We finance a open-source reference implementation. All the children are forever saved from harm. We have parties under rainbows and world peace!

[1] ZKRP's Zero Knowledge Range Proofs: https://arxiv.org/pdf/1907.06381