Two fundamentally different design philosophies

The distinction between permissioned and public blockchains extends beyond technology; it originates from two fundamentally different design philosophies.

Public blockchains were created to eliminate intermediaries and maximize decentralization. Anyone can join the network, operate a node, submit transactions, or become a validator without requiring approval. Platforms such as Bitcoin and Ethereum are well-known examples. This model delivers openness and strong resistance to centralized control, but it also involves trade-offs in performance, governance, and regulatory compliance.

By contrast, permissioned blockchains are designed for environments that require verified identities and clear legal accountability. The network retains core blockchain characteristics such as distributed ledgers, immutability, and data verifiability, while restricting validation rights to pre-approved and verified participants.

This is the model chosen by many national blockchain initiatives because it aligns with the requirements of digital identity, public services, data governance, and digital trust infrastructure.

For national-scale applications, the key question is not which model is "more decentralized," but rather which model achieves a better balance between security, performance, governance, and legal accountability.

Comparing permissioned and public blockchains across key criteria

Network access and participation

The most significant difference between permissioned and public blockchains lies in participation rights.

In a public blockchain, anyone can operate a node, submit transactions, or participate in validation without prior authorization. In contrast, a permissioned blockchain allows only verified and authorized organizations or individuals to operate validator nodes.

🔑 Read more: Permissioned Consensus and Public Consensus: What's the difference?

This distinction forms the foundation for many other differences related to performance, governance, and regulatory compliance.

Consensus mechanisms and performance

Public blockchains typically rely on consensus mechanisms such as Proof of Work (PoW) or Proof of Stake (PoS) to achieve agreement in open, trustless environments. The trade-off is lower throughput and higher latency.

🔑 Read more: Proof of Stake (PoS): What it is and how it differs from PoW and PoA

Permissioned blockchains, on the other hand, commonly use mechanisms such as Proof of Authority (PoA) or Byzantine Fault Tolerance (BFT), where validators are pre-approved and identity-verified.

As a result, these networks can achieve thousands of transactions per second with near-instant finality, making them suitable for national-scale systems serving millions of users.

Tokens and economic models

In public blockchains, tokens are typically central to the ecosystem. They function both as transaction fees and as economic incentives for validators participating in network security and consensus.

Permissioned blockchains do not necessarily require native tokens. Validators participate based on predefined roles, responsibilities, and governance frameworks rather than economic speculation.

This reduces exposure to market volatility, speculative behavior, and other economic factors that may be unnecessary for public infrastructure.

Privacy and regulatory compliance

Public blockchains are designed for maximum transparency, with transaction data often visible across the entire network.

While this transparency provides auditability, it can also create challenges in complying with personal data protection and data governance regulations.

Permissioned blockchains enable role-based access control and policy-driven data governance.

This is one reason why many national blockchain projects and public-sector blockchain initiatives in Europe have adopted permissioned architectures to meet requirements related to privacy, security, and legal compliance.

Accountability and governance

Public blockchains prioritize open decentralization, but assigning accountability when disputes or incidents occur can be difficult because nodes often operate anonymously.

Permissioned blockchains are built on networks of validators with verified identities and clearly defined legal responsibilities.

This structure enables transparent governance, auditing, and oversight mechanisms, making it suitable for high-trust systems such as national blockchains, digital identity platforms, and public services.

Which is better: Permissioned or public blockchain?

There is no blockchain model that is universally superior in every scenario. The choice between permissioned and public blockchain depends on the objectives, operational requirements, and specific use cases involved.

Public blockchains are ideal for ecosystems that require maximum openness and decentralization, where anyone can participate without authorization. They provide the foundation for cryptocurrencies, decentralized finance (DeFi), digital assets, and global networks that operate independently of any central authority.

Permissioned blockchains, by contrast, are designed for systems that require high performance, regulatory compliance, clear governance, and accountability.

This makes them well suited for e-government, digital identity, traceability systems, healthcare, regulated financial services, and especially national blockchain infrastructure.

In addition to these two models, many governments and organizations are exploring consortium blockchains and hybrid blockchains, which combine the validator control of permissioned networks with the transparency and verifiability associated with public networks.

This approach is becoming increasingly popular among national blockchain initiatives because it supports both data sovereignty and independent verification.

The key question, therefore, is not which blockchain is better, but which architecture is better suited to the goals, governance requirements, and trust framework of a given digital infrastructure.

Why do national blockchains choose a permissioned model?

When building a national blockchain to serve governments, businesses, and millions of citizens, the infrastructure must satisfy three core requirements simultaneously:

High performance: Support large transaction volumes with low latency and national-scale scalability.

Regulatory compliance: Ensure personal data protection, auditability, and accountability when required.

Data sovereignty: Maintain control over authentication infrastructure and national data without relying on anonymous external networks.

These requirements explain why most national blockchain initiatives worldwide have adopted permissioned architectures.

Platforms such as the European Blockchain Services Infrastructure (EBSI), Blockchain-based Service Network (BSN), Vishvasya Blockchain Technology Stack, and Keyless Signature Infrastructure (KSI) all operate using permissioned models with identifiable validators and governance frameworks aligned with national requirements.

🔑 Read more: Comparing National Layer 1 Blockchains: How NDAChain, EBSI and BSN Lead the Way

NDAChain: A permissioned national blockchain

NDAChain, Vietnam’s national blockchain platform, is built as a permissioned blockchain powered by the PoA-qBFT consensus mechanism and a public-private validator network whose participants have verified identities and clear legal accountability.

This architecture enables NDAChain to achieve high throughput, near-instant finality, and stable operation at national scale.

🔑 Read more: What is PoA-qBFT? The consensus mechanism of NDAChain Layer 1 blockchain

The permissioned model also enables NDAChain to meet requirements for data governance, privacy protection, and legal compliance under the 2024 Data Law, the 2025 Personal Data Protection Law, and the 2025 Digital Technology Industry Law.

Data is managed through role-based access controls, limiting the exposure of sensitive information across the network.

At the same time, to ensure transparency and prevent excessive concentration of power, NDAChain adopts a multi-layer governance framework that combines regulatory authorities, operating organizations, and independent oversight mechanisms.

The platform is also designed according to open standards to support interoperability with domestic and international digital ecosystems.

For NDAChain, permissioned blockchain does not mean closed or less transparent. Instead, it represents a balanced approach that combines transparency, performance, legal accountability, and data sovereignty - the essential requirements of national blockchain infrastructure.

Conclusion

Permissioned and public blockchains are not competing models; they are different approaches designed for different objectives.

Public blockchains are well suited to open and globally decentralized ecosystems, while permissioned blockchains are optimized for environments requiring high performance, regulatory compliance, accountability, and large-scale data governance.

For national blockchain infrastructure supporting digital government, the digital economy, and digital society, requirements related to data sovereignty, personal data protection, and accountability make the permissioned model a logical choice.

This is also the direction taken by many national blockchain initiatives worldwide.

NDAChain has been built as a permissioned blockchain with the goal of becoming Vietnam’s digital trust infrastructure, combining performance, security, regulatory compliance, and interoperability both domestically and internationally.

Organizations interested in applying national blockchain technology for digital identity, data authentication, traceability, and digital transformation can learn more about NDAChain’s architecture and ecosystem at ndachain.vn.