1. Estonia and its journey to digitizing 99% of public services

Estonia is one of the world's leading examples of digital government. Since the early 2000s, this Baltic nation of approximately 1.3 million people has invested in digital infrastructure to move the vast majority of public services online. According to the e-Estonia portal, around 99% of Estonia's public services can now be accessed online, from tax filing and business registration to electronic voting. Only a few services such as marriage, divorce, and real estate transactions still require citizens to be physically present.

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Estonia's success is not the result of a single application, but of a well-designed national digital architecture. Within this architecture, X-Road serves as the data interoperability platform connecting government agencies, while KSI Blockchain ensures the integrity and verifiability of government data. This provides an important lesson for countries developing national blockchain infrastructure: digitizing public services should begin with digital trust infrastructure, not with isolated applications.

2. What is X-Road? The backbone of Estonia's data interoperability

X-Road is a distributed data exchange platform that enables information systems across government agencies and private-sector organizations in Estonia to communicate securely. Instead of creating one massive centralized database, X-Road allows each organization to retain ownership of its own data while providing a standardized and secure layer through which systems can query, authenticate, and exchange information whenever needed.

The core characteristics of X-Road include:

• Decentralized architecture: Each organization manages its own data, while X-Road provides a secure communication channel.

• The once-only principle: Citizens only need to provide information once. Government agencies can retrieve existing verified data instead of requesting the same information repeatedly.

• Security and audit logging: Every request is encrypted, digitally signed, and logged for auditing, monitoring, and accountability.

• Large-scale interoperability: X-Road connects thousands of services across hundreds of organizations, providing the foundation for an integrated digital government.

Through X-Road, Estonia has significantly reduced duplicate data entry, manual verification, and paper-based administrative processes. The X-Road model demonstrates that building a digital government or a national blockchain, is not simply about digitizing individual services. The real foundation lies in creating secure, interoperable, verifiable, and accountable data infrastructure.

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3. What is KSI Blockchain? Estonia's data integrity infrastructure

KSI (Keyless Signature Infrastructure) is the blockchain infrastructure deployed by Estonia to ensure the integrity and verifiability of government data. Rather than storing data directly on the blockchain, KSI generates a cryptographic hash for every record and anchors that hash on the blockchain, enabling anyone to verify that the underlying data has remained unchanged throughout its lifecycle. What distinguishes KSI is its keyless architecture. According to Guardtime, the system relies on cryptographic hash functions and blockchain structures to verify data integrity without depending on long-term secret keys, thereby reducing risks associated with compromised keys or future advances in cryptography.

The major benefits of KSI include:

• Ensuring data integrity: Any unauthorized modification is immediately detectable through hash verification.

• Proof of existence: Records can be proven to have existed in a specific state at a particular point in time.

• Privacy protection: Only cryptographic hashes are stored on the blockchain, while the original data remains off-chain.

• Long-term trust: Without relying on long-term secret keys, the system is more resilient to future changes in cryptographic technologies.

KSI demonstrates that blockchain does not need to store all data to establish trust. Ensuring data integrity and verifiability alone can provide a reliable foundation for digital government and national blockchain infrastructure. This principle also underpins many modern blockchain architectures, including NDAChain.

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4. How do X-Road and KSI complement each other?

X-Road and KSI Blockchain are two distinct infrastructure layers that work together to support Estonia's digital government architecture. X-Road addresses the challenge of data interoperability, enabling government agencies and private-sector organizations to exchange information securely without relying on a centralized database. KSI, on the other hand, addresses the challenge of data trust by ensuring that records used across the system remain tamper-proof and verifiable throughout their lifecycle.

In other words, X-Road enables data to move securely, while KSI ensures that the data can be trusted.Together, these two infrastructures create a digital ecosystem where information can be shared efficiently across organizations while its origin, integrity, and historical state remain fully verifiable.

This offers an important lesson for countries developing national blockchain infrastructure: digital transformation requires not only a data exchange layer, but also a digital trust layer that guarantees the integrity of every piece of shared information.

5. Lessons for Vietnam's national blockchain infrastructure

Estonia's model demonstrates that digitizing public services is not simply about moving individual procedures online. It is about building a shared digital infrastructure consisting of two essential layers: a data interoperability layer and a digital trust layer. This is also an important lesson for Vietnam as it develops its national blockchain and national data infrastructure.

• Digital transformation begins with infrastructure: Rather than developing isolated applications for individual government agencies, Vietnam needs a common platform for secure data interoperability, authentication, and verification across the entire public sector.

• Blockchain should anchor proofs, not expose data: Like Estonia's KSI, NDAChain can use blockchain to anchor cryptographic hashes that verify data integrity while keeping sensitive personal information off-chain. This approach preserves privacy without sacrificing transparency or trust.

• Data interoperability is fundamental: Government agencies must be able to manage and exchange verified data securely across systems through standardized protocols.

• The once-only principle: Citizens and businesses should never be required to submit the same verified information multiple times. Once data has been authenticated, authorized agencies should be able to retrieve it through secure cross-agency data sharing.

🔑 Read more: Vietnam's national blockchain: Lessons from Estonia, the EU, China, Singapore, and India

With a throughput of 1,200 TPS, compliance with W3C DID/VC standards, and support for digital identity and secure data sharing, NDAChain provides the technical foundation for building a national digital trust layer for public services, digital identity, and cross-agency data exchange in Vietnam.

6. From Estonia to Vietnam: building digital trust infrastructure for digital government

Estonia's experience demonstrates that digitizing 99% of public services was not achieved through a single breakthrough application. Instead, it was made possible by a well-designed digital infrastructure in which X-Road provides secure data interoperability across government agencies, while KSI Blockchain establishes the trust layer that ensures information remains verifiable and tamper-proof.

With a significantly larger population and a more complex administrative system, Vietnam requires an infrastructure-first approach rather than digitizing individual services independently. The country's advantage lies in its ability to learn from proven international models while building infrastructure tailored to its own legal, institutional, and technological context.

Within this vision, NDAChain can serve as the digital trust layer of Vietnam's national blockchain, complementing the country's national data interoperability strategy to build a digital government where public services are not only more convenient, but also more transparent, secure, and trustworthy.

Frequently asked questions (FAQ)

How did Estonia digitize 99% of its public services?

Estonia achieved the digitalization of approximately 99% of its public services through a carefully designed national digital architecture. Within this architecture, X-Road serves as the data interoperability platform connecting government agencies, while KSI Blockchain ensures the integrity and verifiability of government data. This success was not driven by a single application but by a shared digital infrastructure spanning the entire public sector.

What is X-Road?

X-Road is a distributed data exchange platform that enables government agencies and private organizations to communicate securely. Instead of relying on a centralized database, each organization retains control of its own data while sharing information through standardized, encrypted, digitally signed, and fully auditable communication channels.

What is Estonia's KSI Blockchain?

KSI (Keyless Signature Infrastructure) is Estonia's blockchain-based infrastructure for ensuring data integrity. It generates a cryptographic hash for every record and anchors that hash on the blockchain, allowing anyone to verify that the underlying data has not been altered without storing the original data on-chain. This approach protects privacy while maintaining full verifiability.

What is the difference between X-Road and KSI?

X-Road solves the challenge of data interoperability, allowing information to move securely between organizations. KSI Blockchain solves the challenge of data trust, enabling organizations to prove that information has not been tampered with. Together, they form a two-layer digital infrastructure consisting of a data exchange layer and a digital trust layer.

What can Vietnam learn from Estonia's model?

The key lesson is that digital government should begin with shared digital infrastructure, including secure data interoperability and a trusted digital layer, rather than isolated digital applications. In Vietnam, platforms such as NDAChain can serve as the country's national blockchain, providing data integrity, digital identity support, secure cross-agency data sharing, and a trusted foundation for a more transparent and secure digital government.