Vietnam’s Blockchain ID Could Guide Aadhaar On How To Stop Oversharing

For Indians, Aadhaar has been both a blessing and a bit of a headache. On paper, it’s brilliant: a universal ID that works across the country, helps people get subsidies, open bank accounts, access government schemes, and even get admission to schools and colleges.

But in reality, it sometimes feels like we’re handing over our entire identity to prove a simple fact: we exist. Need a SIM card? Aadhaar. Want to file income tax? Aadhaar. Apply for a scholarship? Again, Aadhaar.

And as more services pile onto it, a question keeps coming up: is Aadhaar doing too much, without giving us enough control?

Turns out, halfway across Asia, Vietnam is trying something unique with its own national identity infrastructure, and it might have a few lessons for us.

Vietnam’s Bet on Tech

On July 25, Hanoi launched something called NDAChain, a national blockchain platform designed to support everything — from digital identity and electronic signatures to supply chain tracking and health records.

What makes NDAChain interesting isn’t just that it uses blockchain. It’s how it uses it. It’s built on a permissioned model, which means only government agencies and verified institutions can be part of the system.

One of its features is the use of zero-knowledge proofs (ZKPs). In simple words, it lets you prove a fact about yourself — like being over 18 or eligible for a benefit — without revealing any data about yourself.

That’s one feature our very own Aadhaar lacks. But it’s a problem that can be solved. Let’s see how.

An Overworked Aadhaar

Aadhaar was designed as a simple ID for Indians. But over the years, we have started using it for things it wasn’t built for: verifying transactions, linking bank accounts, tracking subsidies, and so on.

While it works well for all these services, it also raises serious concerns around surveillance, data leaks, and lack of consent.

RS Sharma, the former TRAI chairman, understands this. In a recent talk with The Core, he said it’s time to build a privacy-focused layer on top of Aadhaar. Something programmable, secure, and respectful of consent.

What Sharma said does not amount to “let’s do what Vietnam’s doing”. But Vietnam’s NDAChain feels like a working version of the kind of system he’s talking about. A place where people don’t have to overshare just to access what’s rightfully theirs.

What Needs To Change

We already have a sophisticated digital public infrastructure in Aadhaar, DigiLocker, UPI, and more. What’s missing is an element that preserves privacy and verifies identity without exposing a user’s credentials.

To build in the privacy element in Aadhaar, India, like Vietnam, could use a permission-based blockchain where only selected participants are allowed to join the network. That way it could be controlled and validated by the government and a few trusted institutions, unlike on a public blockchain where all records are visible to anyone who joins the network.

This is where ZKPs (zero-knowledge proofs) become critical to this vision. ZKPs let someone prove they are entitled to a benefit without revealing unnecessary personal data. Perfect for Aadhaar-linked benefits and eligibility proofs.

In 2024, a Hyderabad-based company introduced ZKP blockchain tech that allows verification of data without exposing any user credentials. That could be a place to start.

Then comes identity management, which is essential because it answers the fundamental question, “Who are you?”, across every digital interaction.

For this, we could go for an open-source framework — perhaps like the one Infosys used to issue verifiable credentials — which lets different systems talk to each through a standard protocol.

In this system, citizens hold their own wallet, a secure app that stores information about a person’s identity, and control what they share.

So, this is how the two systems — identity management and ZKP — work together:

Identity management says, “This is who I am.” And then ZKP steps in, saying, “Here’s what you need to know about me without getting my credentials.”

Hypothetically, if Aadhaar were to adopt this system, this is how you might need to go about taking, let’s say, a new mobile connection:

As of today, you visit a store, share your Aadhaar number and biometric or OTP. In the new system, you walk in, scan a QR code, and your digital wallet asks you to authenticate your identity verification request. There would be absolutely no need to reveal your Aadhaar number or date of birth.

Final Words

Let’s make one thing clear: this isn’t about turning Aadhaar upside down. What Vietnam is building, and what India could too, is a digital public infrastructure on blockchain. You may call it Aadhaar 2.0, with better privacy settings.

In short, we don’t need to copy Hanoi. But their example shows it’s possible to modernise a national ID system in a way that’s secure and respectful of users.

Aadhaar helped build Digital India. Maybe it’s time to build something that also protects the digital identity of Indians.

But tech is just one piece of the puzzle. India would also require stronger data protection laws, and need to be willing to move away from storing everything centrally to sharing only what’s needed.

This series is brought to you in partnership with Algorand.