Why Estonia turned to blockchain for healthcare
Traditional healthcare systems worldwide face numerous data management challenges.
Weak data security: electronic health records are an attractive target for cyberattacks, as health data commands high value on black markets.
Lack of transparency: patients often have no way of knowing who accessed their records, when, or why.
Fragmented systems: health information is siloed across hospitals and clinics with no interoperability, leaving doctors without a complete picture.
High management costs: maintaining centralized systems is both expensive and creates a single point of failure once breached, the entire data repository is at risk
🔑 Read more: Estonia: the pioneering nation in applying blockchain to national healthcare system
According to widely cited estimates (Ponemon Institute), in the United States alone, the cost of healthcare data breaches runs into billions of dollars annually, while healthcare fraud globally causes hundreds of billions of dollars in losses. This is the real-world problem Estonia was determined to solve, not because blockchain was fashionable, but because it worked.
Estonia's blockchain solution
In 2016, the Estonian eHealth Foundation partnered with technology company Guardtime to deploy a groundbreaking project: applying blockchain to protect the health records of over one million citizens. This is widely regarded as one of the world's first instances of blockchain being deployed in a national healthcare system at scale, while significantly enhancing the transparency and auditability of health data.
At the core of the solution is KSI Blockchain (Keyless Signature Infrastructure) technology developed by Guardtime. This technology has three defining characteristics.
First, KSI is not built on cryptocurrency or tokens, it is purpose-designed for large-scale sensitive data systems.
Second, the platform uses hash-based cryptography, enabling data integrity verification without dependence on a single intermediary authority.
Third, KSI operates as a national-scale timestamping system, protecting the integrity of digital documents across multiple sectors including healthcare, property registration, and the judiciary.
🔑 Read more: National blockchain in digital healthcare: When patient records belong to the patient
The deployment model consists of four main layers.
The first is the KSI Blockchain, which ensures data integrity.
The second is an activity log system that records every data access and processing action.
The third is a decentralized authentication mechanism that eliminates the vulnerabilities of traditional centralized models.
The fourth is an access control system that allows citizens to track who accessed their data, at what time, and for what purpose.
Artur Novek, Director of Deployment and Architecture at the Estonian eHealth Foundation, has stated: "We use blockchain as an additional security layer to ensure the integrity of health records. The privacy and integrity of healthcare data has always been the government's top priority."
Health data is NOT stored on the blockchain
This is an important technical point that is frequently misunderstood when blockchain is mentioned in the context of healthcare. Estonia does not store medical records directly on the blockchain. Instead, health data continues to be held in specialized database systems, Estonia uses the Oracle platform to manage electronic health records.
KSI Blockchain is integrated at the data verification layer to perform three core functions: ensuring data integrity and immediately detecting any unauthorized changes; recording and auditing the complete history of access; and supporting transparent, traceable data lifecycle governance.
🔑 Read more: Comparing national Layer 1 blockchains: how NDAChain, EBSI, and BSN lead the way
In other words, blockchain does not serve as a repository for health records, it is the digital seal and verification ledger for the entire system. Health data continues to be managed in databases that comply with personal data protection regulations, while blockchain stores only cryptographic proofs to demonstrate that data has not been altered and to accurately record who accessed it and when.
It is precisely this approach that allows Estonia to simultaneously achieve two seemingly contradictory goals: ensuring data integrity at national scale while protecting the privacy of citizens. This architectural principle is also being adopted by many modern blockchain infrastructures, including NDAChain, which stores data off-chain while blockchain serves as the verification, authentication, and traceability layer.
A unique proposition: blockchain for healthcare at national scale
Estonia has built a highly distinctive position in digital health: using blockchain as a protection layer for the entire national healthcare ecosystem. This model delivers four core values, national-scale security, transparency in data access, guaranteed integrity of health records, and greater patient control over personal health information.
As a result, patients can track who accessed their records, when, and for what purpose. Any changes to data are recorded, and unauthorized interventions can be detected. Citizens are also empowered to decide who is permitted to access their health data.
🔑 Read more: Why is Vietnam building a national blockchain platform?
Notably, Estonia does not use blockchain only to protect health records. The technology is integrated across the entire national e-health ecosystem, including the E-Prescription system, E-Ambulance emergency management, and the Patient Portal. These services are connected through the X-Road data interoperability platform, forming a unified national digital ecosystem.
Estonia's success did not come from a short-term project. The country began applying blockchain to protect digital data, services, and devices from 2008, operating at real scale from 2012, and partnering with Guardtime from 2011 before expanding into healthcare in 2016. This is the result of a long-term digital infrastructure strategy, implemented incrementally and consistently over many years.
Why Estonia's model has become a global benchmark
According to e-Estonia, dozens of governments and many international organizations have visited Estonia to study how blockchain is applied in healthcare and public services. What makes this model highly regarded is its ability to solve real-world problems in data security and governance, rather than chasing technology trends.
🔑 Read more: Tokenless Layer 1 blockchain: why national blockchain doesn't need a token
Siim Sikkut, former Chief Information Officer of the Estonian Government, has said: "We didn't adopt blockchain because it was trendy. We adopted it because it solves a real problem: protecting people's health data."
From Estonia's experience, four core principles can be drawn: use tokenless blockchain for public infrastructure; never store personal data on-chain, only store integrity proofs; give citizens control and transparency; and integrate blockchain into an interoperable data ecosystem rather than deploying it as a standalone solution.
Lessons for Vietnam and the role of NDAChain
Vietnam is accelerating its healthcare digital transformation with the goal of universalizing electronic health records and building a nationally interoperable health data system. The challenges Estonia once faced, data security, transparency, and system fragmentation are also Vietnam's challenges, but at the scale of over 100 million people. Notably, the approach Estonia chose shares many similarities with NDAChain's architecture the platform designed to be Vietnam's national blockchain.
NDAChain inherits the core principles that contributed to Estonia's model success. It is a tokenless Layer 1 blockchain, designed to serve public infrastructure and national data use cases rather than speculative purposes. Like KSI Blockchain, NDAChain does not store personal data directly on-chain, it records only cryptographic proofs, combined with Zero-Knowledge Proof technology to protect privacy. This approach reflects the principle that "blockchain is the data verification and sealing layer, not the data storage layer," and is consistent with the requirements of the 2025 Personal Data Protection Law.
🔑 Read more: Zero-Knowledge Proof on Layer 1 blockchain: securing data without revealing information
In addition, NDAChain operates on a PoA-qBFT consensus mechanism with a network of clearly identified public and private validator nodes carrying specific legal accountability, ensuring data integrity and traceability similar to how Estonia protects health records from unauthorized changes.
More importantly, NDAChain can become the digital trust layer for Vietnam's entire healthcare ecosystem. The platform supports protecting the integrity of electronic health records and logging data access history in the same manner as Estonia's KSI model; provides digital identity for patients, healthcare facilities, and medical personnel through NDADID; and enhances transparency and traceability of pharmaceuticals and medical supplies through NDATrace, helping to combat counterfeit drugs and fraud in the healthcare supply chain. This is how Vietnam can follow the path Estonia has proven effective but on a national blockchain infrastructure researched, developed, and owned by the Vietnamese themselves.
🔑 Read more: Building digital trust: The foundation for a prosperous Vietnam
The most important lesson from Estonia is not "use blockchain", it is "choose the right type of blockchain for the right problem." A tokenless national blockchain infrastructure that protects data integrity, respects privacy, and integrates into an interoperable data ecosystem is exactly the model NDAChain is working toward to serve Vietnam's digital transformation.
From Estonia to Vietnam: building trust for health data
Estonia has demonstrated to the world that blockchain can protect health data at the national level in a practical and sustainable way, not by putting records on-chain, but by using blockchain as the integrity and transparency layer for the digital health system. With over one million records protected and a complete e-health ecosystem in place, Estonia's model is a benchmark Vietnam can learn from. And with NDAChain, a national blockchain platform that shares Estonia's design philosophy, Vietnam has the foundation to realize a healthcare system that is secure, transparent, and self-reliant.
👉 Learn more about NDAChain and its applications in digital health at https://ndachain.vn/en
