
Zero-knowledge proof in action: Current and potential applications
As digital services take on a larger role in our daily lives, many routine tasks now require users to provide extensive personal information, often through lengthy forms or ID uploads. For users, this can feel cumbersome; for organisations, it creates operational inefficiencies and adds the complexity of managing sensitive data.
In sectors such as retail, e-commerce, peer-to-peer marketplaces, mobility services, and media platforms, full identity verification is often more than necessary. Collecting and storing all this information places a strain on internal processes. It also comes with strict regulatory obligations under GDPR and the Digital Services Act. The combination of operational burden, compliance requirements, and limited added value is prompting companies to reconsider how much data they truly need to collect.
The resulting drive towards
This blog explores how different sectors are replacing full identity verification with lightweight checks to confirm whether a user meets the necessary criteria, benefiting both users and businesses. It also highlights potential implementations across various industries.
Identifying vs. qualifying a customer: What is the difference?
Traditional identity verification attempts to answer the question: “Who is this user?” It collects full names, birthdates, addresses, or government IDs, even when only a single piece of information is relevant.
Qualifying a customer, on the other hand, flips the question. It answers: “Does this user meet the specific requirement that matters right now?” To answer this question, a simple yes/no answer is sufficient.
Using
Platforms like digital identity platform itsme® embed ZKP functionality directly into the user experience, allowing businesses to verify what exactly matters at the point of interaction.
ZKP in action: Examples of proportional identification across sectors
Currently, the most common applications of ZKP focus on verifying if a user is within the acceptable age limit to access a certain service or product, as we explore below:
Retail & E-commerce: In Germany, public cigarette vending machines must legally prevent underage purchases. Payment terminals for vending machines known as KarL4 integrate age verification directly into the payment process using the girocard, Germany’s national debit card system. When a customer taps their card, the terminal confirms that they are at least 18 without storing personal data. By confirming eligibility without collecting full identity information, this example illustrates how privacy-preserving verification can be applied at scale.
Streaming & media platforms: In France, the government has introduced a
new age verification standard to protect minors from harmful online content. This standard goes beyond simple self-declarations, requiring rigorous checks such as digital ID verification, while ensuring double anonymity. This means that age verification providers and the sites themselves cannot identify users or track their activity. Similarly, adult content platform BlissFlix allows content creators to verify that they are above 18 years oldusing zero-knowledge proof , ensuring that only a yes/no value indicating age verification status is stored. In both examples, age is simply confirmed without exposing personal data, aligning with privacy-first and data minimisation principles.Peer-to-Peer Marketplaces: Dating application Bumble is among the first consumer platforms to adopt ZKP technology for age verification, confirming users' eligibility without ever seeing the underlying data. Instead of asking users to submit full ID documents or disclose exact birthdates, Bumble leverages ZKPs via Google Wallet to allow users to prove they meet the platform’s age requirements without revealing any additional personal information.
Crypto and digital assets: One of the first and most known applications of zero-knowledge proof technology emerged in the cryptocurrency sector around 2016. Since then, ZKPs have become central to blockchain innovation, allowing exchanges and wallets to comply with strict anti-money laundering and KYC requirements without overburdening users or storing sensitive identity data. For example, Concordium's blockchain-based solution offers a privacy-first identity verification system. Using ZKPs, it verifies age without exposing personal data, making it suitable for platforms dealing with age-restricted content or services.
Emerging opportunities for zero-knowledge proof
Besides age verification, ZKP-based solutions can enable users to prove specific eligibility criteria, such as residing in an allowed jurisdiction, being an actual human, not appearing on a sanctions list, etc. while protecting full identity details. For instance:
Ride-sharing and mobility apps could confirm with ZKP that a driver meets license requirements without requiring full KYC checks or storing sensitive identity documents. Shared mobility platforms, such as e-scooter rentals across Europe, could confirm a user’s eligibility at account creation without storing sensitive documents like passports or birthdates.
eLearning providers could verify student enrolment to grant discounted access without exposing full academic records or institutional details, checking only for the relevant attribute, e.g. “currently enrolled”.
Social platforms could reduce fake accounts and prevent bots by using ZKP-based proof of humanity checks without requesting ID uploads. This form of verification ensures real people are behind accounts, which helps protect community integrity and reduces the risk of spam, scams, and misinformation.
Peer-to-peer marketplaces could apply proof of humanity to reduce fraudulent activity. For instance, sellers could prove they are real individuals without having to disclose personal details, making the platform safer while keeping onboarding smooth.
Streaming and digital content providers can confirm a user’s country of residence to comply with licensing restrictions. For example, a film made available only in a certain country could be unlocked by proving “residence in X country” without sharing an address or national ID number. This helps providers enforce rights agreements while giving users a seamless experience.
Public transportation providers could check eligibility for student, senior, or disability benefits using a simple cryptographic yes/no proof, ensuring minimal data collection.
Events and venues could allow attendees to prove they are over 18 for R-rated movies or alcohol-serving concerts without sharing full birthdates, improving both privacy and efficiency in busy settings.
While implementing ZKPs can be technically challenging, platforms can integrate the technology easily through trusted services like
Conclusion
Minimum disclosure is increasingly becoming a regulatory requirement, a commercial advantage, and a foundation for digital trust. With GDPR enforcement tightening and the European Digital Identity framework on the horizon, Europe is clearly moving towards a future where less is more in identity verification.
Proportional verification and zero-knowledge proof demonstrate that compliance and customer experience can go hand in hand. Real-world applications show that by collecting only what is strictly necessary, businesses reduce liability, lower costs, and streamline onboarding, while signalling to customers that their privacy is valued. This approach turns data minimisation from a regulatory obligation into a strategic advantage, fostering trust, efficiency, and sustainable growth.
Companies that adopt minimum disclosure early will not only be prepared for upcoming EU digital identity standards but also gain a competitive edge. Solutions like itsme® Qualify make it easier to incorporate zero-knowledge proofs into existing operations, helping businesses build trust, reduce fraud risks, and explore privacy-first business models.