Zero Knowledge Proof (ZKP) + SSI for Age Verification
In Venice, we must begin to discuss this.
I don't like that AI services are becoming permissioned and are not remaining permissionless like Bitcoin, but that's the way it's going.
Reasons
New Age Verification Laws for Chatbots in the United States
A bill called the "Guidelines for User Age-verification and Responsible Dialogue Act of 2025" is already being proposed that would require AI services to request age verification in the United States; in the references, I have included the first article[^1] and the second[^2].
The case of Australia
In Australia, they want to prevent minors from accessing AI characters[^3]. Before the laws were passed, the Character AI service put measures in place to identify whether users are of legal age [^4].
Character AI now uses the 'Persona' verification service to allow users to upload their documents and/or identification credentials; if verification fails, the user will be asked for facial recognition.
Data leaks
I don't like uploading identification documents to dozens of verification sites, and I like facial recognition even less. remember what happened with Discord and its security breach[^5] where more than 70,000 photos of government IDs were leaked, as well as the case of 'Tea App' where more than 13,000 selfies were leaked[^6], selfies that according to Tea App "were deleted when they were no longer needed", which turned out to be a lie.
Why Age Verification in Venice?
Venice offers the option to chat with characters, image-generating AIs, and videos with low censorship.
Remember that Venice is a service that gives high priority to privacy, which is why we need Zero Knowledge Proof + Self-sovereign identity (SSI).
Zero Knowledge Proof (ZKP)
Single issuer: Users only need to identify themselves to a single issuer of identifiers and can use that cryptographic identifier to verify themselves on other services. This significantly reduces the risk of data leaks.
Only the necessary information: A service (let's say Venice) using a cryptographic proof will only know what it needs to know, that the user is of legal age (without having to provide a date of birth), and nothing else, no full name, address, etc.
Not traceable: It is not traceable by the ID issuer. This significantly increases user privacy.
More about ZKP: In the references below, I have included a link to the first video[^7], second video[^8], and a Wikipedia article[^9].
Self-sovereign identity (SSI)
Control: Gives individuals complete control over their credentials and allows them to decide when and with whom they are shared.
Self-custody: Credentials are held by the user (digital wallet, private keys, etc.).
Decentralization: SSI is based on decentralized models (blockchain, DIDs, etc.) where there is no single point of authority.
Mechanisms: SSI includes user-controlled revocation, expiration, and update mechanisms.
More about SSI: In the references below, I have included a link to the first video [^10] and an article [^11].
Preferences for ZKP + SSI
Open Source: The tools to be used should be open source.
Independence from restrictive systems: The tools should not depend on restrictions such as Google Play Integrity or similar, so that they can also be used on operating systems and tools that respect privacy, such as:
Browser extensions (Brave, Firefox, and in the future Ladybird)
Android smartphones without Google Play Services (de-Googled phones)
Desktop operating systems such as GNU/Linux, etc.
In the future, smartphones with GNU/Linux OS
Specialized hardware (such as Ledger and Concordium)[^12]
Implementation
Request age verification only in countries where it is required by law.
Some options I have researched
The app is open source and can be downloaded from GitHub without going through the Google Play Store
It has open source AppImage and .deb package for GNU/Linux
Extras
Venice Audit
Although Venice provides more confidence in terms of privacy than other services such as OpenAI, there is still no audit.
Eventually, when age verification becomes mandatory, it would not be ideal to continue with just "Trust me bro".
It would be good for an auditor to check at least these two things about Venice:
The AIs are not trained with user prompts.
There are Zero Logs of user prompts.
Acknowledgments Venice
I would like to thank Venice for removing Google Fonts from the Chat page. Google uses Google Fonts to track users.
References
[^1]: [Article: Lawmakers Want Proof of ID Before You Talk to AI](https://reclaimthenet.org/lawmakers-want-proof-of-id-before-you-talk-to-ai)
[^2]: [Article: Senators announce bill that would ban AI chatbot companions for minors](https://www.nbcnews.com/tech/tech-news/ai-ban-kids-minors-chatgpt-characters-congress-senate-rcna240178)
[^3]: [Article: Australia's eSafety Chief Pressures Big Tech and AI Firms on Verification, Age Checks](https://reclaimthenet.org/australia-online-speech-crackdown-esafety-age-verification-push)
[^4]: [Article: Character AI is ending its chatbot experience for kids](https://techcrunch.com/2025/10/29/character-ai-is-killing-the-chatbot-experience-for-minors/)
[^5]: [Article: Discord says the identifying data of 70,000 users may have been leaked in a security breach](https://www.theverge.com/news/797051/discord-government-ids-leaked-data-breach)
[^6]: [Article: Hackers leak 13,000 photos and user IDs from Tea app, designed as a safe space for women](https://www.nbcnews.com/tech/social-media/tea-app-hacked-13000-photos-leaked-4chan-call-action-rcna221139)
[^7]: [YouTube video (07:18 minutes): Zero-knowledge proof: the only secure way to verify age (why no one talks about it)](https://www.youtube.com/watch?v=KIoj9oMXE_0)
[^8]: [YouTube video (22:35 minutes): A computer scientist explains a concept in 5 levels of difficulty | WIRED](https://www.youtube.com/watch?v=fOGdb1CTu5c)
[^9]: [Wikipedia: Zero-knowledge proof](https://en.wikipedia.org/wiki/Zero-knowledge_proof)
[^10]: [YouTube video (02:57 minutes): Explanation of self-sovereign identity (SSI)](https://www.youtube.com/watch?v=kJAapPG_jBY)
[^11]: [Article: Self-Sovereign Digital Identity](https://www.concordium.com/article/self-sovereign-digital-identity)
[^12]: [Article: Ledger and Concordium bring age-verified payments to millions of people](https://www.concordium.com/article/ledger-and-concordium-bring-age-verified-payments-to-millions)
[Concordium: A New Dawn in Digital Identity](https://www.linkedin.com/pulse/concordium-new-dawn-digital-identity-david-mygind)
[Self-sovereign identity](https://en.wikipedia.org/wiki/Self-sovereign_identity)
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Comments1
Coral Deer
Nov 2, 2025
Since I can't edit my post, I'll be posting updates in this comment.
Update 1
Corrections
The bill called the “Guidelines for User Age-verification and Responsible Dialogue Act of 2025” or “GUARD Act” was not proposed but is already being drafted, which is even worse.
Additional information
New section (top): Cost reduction
A traditional KYC service: Can cost between $1 and $10 (or more) per verification
ZKP+SSI solution on an efficient network (Concordium, Polygon, etc.): Cost per verification less than $0.01
In the section ‘Preferences for ZKP + SSI’, the following is added:
Protocols, not platforms: Always prefer protocols to maximize compatibility and freedom of choice over technologies that only work on one platform.
I have read that there are Digital Identity applications in the European Union and Switzerland, but that these depend on Google Play Integrity, which is ironic, since according to the European Union, they seek Digital Sovereignty, but are forcing their citizens to depend on American technologies and, above all, on the corporation that least respects privacy in the entire Western world, Google.
Updated information
Header Update
The name of the header has been changed from “Extras” to “Optional but recommended.”
Update of the entire Concodium section:
Concordium:
Browser Extension
- Has an extension for Chromium-based browsers
- Is it open source? Yes
- License: Apache 2.0
- Chrome Web Store
- GitHub
- Note: At the moment, the crx files are not available for direct download, but you can ask the developers to upload them so that we don't have to rely on the Chrome Web Store. You can also ask them to compile a version for Firefox.
Android app
- Is it open source? Yes
- License: Apache 2.0
- GitHub
- Note: Some states in the United States want to enforce age verification in order to download any app from the Google Play Store or App Store, so it's a good idea to look for apps that can be downloaded outside of the stores, as in this case, where it can be downloaded from GitHub.
We can ask the Concordium developers to make the app available on F-Droid or to have their own F-Droid repository.
Linux, macOS and Windows
- It has AppImage and .deb package for GNU/Linux
- Is it open source? Yes
- License: Apache 2.0
- GitHub
- Note: It also has rpm for Fedora, exe for Windows, and dmg for macOS.
- At the moment, Concordium is seen as the best option because it meets the requirements of the ‘Preferences for ZKP + SSI’ section.
Updated Private ID link:
Privado ID (formerly Polygon ID)
Links 5 and 6 replaced by Reclaim The Net:
[^5]: Article: Discord Support Breach Exposes Over 70,000 Government IDs
[^6]: Article: Tea App Leak Shows Why UK’s Digital ID Age Verification Laws are Dangerous