Permissioned Consensus và Public Consensus: Khác nhau như thế nào?

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Permissioned Consensus and Public Consensus: What's the difference?06/15/2026

(ndachain.vn) Permissioned consensus and public consensus are two core consensus models that determine how a blockchain operates, who has the right to validate transactions, and the degree of network control. While public consensus allows anyone to participate in validation through mechanisms such as Proof of Work (PoW) or Proof of Stake (PoS), permissioned consensus only allows organizations or entities with verified identities to participate in operating the network. Each model has its own strengths in terms of decentralization, performance, security, and governance capability. This is also why national blockchains and large-scale data infrastructure typically choose the permissioned model over public blockchain. This article analyzes the differences between permissioned consensus and public consensus, and explains why NDAChain chose the PoA-qBFT mechanism to build national digital trust infrastructure.

1. What is public consensus?

Public consensus is the consensus model used on public blockchains, where any individual or organization meeting the technical requirements can participate in validating transactions and operating the network without prior authorization. This is the foundation of blockchains like Bitcoin and Ethereum, with the goal of maximizing decentralization and resistance to centralized control.

Characteristics of public consensus:

Open and permissionless: Anyone can participate as a validator or miner.
High degree of decentralization: Validation rights are distributed among thousands of independent nodes worldwide.
Uses popular consensus mechanisms: Most notably Proof of Work (PoW) and Proof of Stake (PoS).
Trust based on economic incentives: Network security is ensured through computational cost, staking mechanisms, or other economic incentives.

Thanks to its openness and resistance to control, public consensus is particularly well-suited for public blockchains and global digital asset ecosystems. However, this model typically involves trade-offs in performance, governance capability, and network resource consumption.

2. What is permissioned consensus?

Permissioned consensus is the consensus model used in permissioned blockchains, where only organizations or entities that have been identity-verified and pre-approved may participate in validating transactions and operating the network. Unlike public blockchains, the list of validator nodes is governed according to clear rules and oversight mechanisms.

Characteristics of permissioned consensus:

Licensed and identity-verified validators: Only qualified organizations may participate in validation, and they can be added or removed according to governance rules.
High performance and scalability: The controlled number of validators allows the network to achieve high processing speeds and near-instant finality.
Uses specialized consensus mechanisms: Most common are Proof of Authority (PoA) and Byzantine Fault Tolerance (BFT) algorithms such as qBFT on Hyperledger Besu.
Trust based on legal accountability: Network security is ensured by the identity, reputation, and legal obligations of participating validators.

Thanks to transparent governance, high performance, and ease of accountability, permissioned consensus is particularly well-suited for enterprise blockchains, national data infrastructure, digital identity, traceability, and systems requiring strict legal compliance.

3. How do permissioned and public consensus differ?

The core differences between permissioned consensus and public consensus

Although both aim to help nodes reach consensus on data and transactions, permissioned consensus and public consensus are designed for entirely different operating environments.

Core differences between the two models:

Participation: Public consensus allows anyone to participate in transaction validation, while permissioned consensus is restricted to authorized validators.
Validator identity: On public blockchains, validators or miners typically operate anonymously or semi-anonymously; by contrast, permissioned blockchains require clearly verified identities.
Consensus mechanism: Public consensus typically uses Proof of Work (PoW) or Proof of Stake (PoS), while permissioned consensus is most commonly associated with Proof of Authority (PoA) and Byzantine Fault Tolerance (BFT) algorithms such as qBFT.
Processing performance: Permissioned consensus can achieve high TPS and near-instant transaction finality, while public consensus typically trades off performance for a higher degree of decentralization.
Resource consumption: Public blockchains using PoW have high energy consumption, while permissioned consensus operates significantly more efficiently.
Source of trust: Public consensus relies on economic mechanisms and open consensus rules; permissioned consensus relies on the identity, reputation, and legal accountability of validators.
Accountability: Permissioned blockchains allow clear identification of the operating entity and the responsibility of each validator, which is more difficult to achieve on public blockchain networks.

These differences are precisely what make public consensus suited to public blockchains and global digital assets, while permissioned consensus has become the popular choice for enterprise blockchains, public services, and national data infrastructure.

4. Which objectives does each consensus model suit?

There is no single blockchain consensus model that is best for every situation. Public consensus and permissioned consensus are designed to address different problems, with different priorities around decentralization, performance, and governance.

Public consensus suits:

Public blockchains and global digital assets
Decentralized applications (DApps) operating in open environments
Systems without a trusted intermediary that require a high degree of decentralization
Networks where trust is established through economic mechanisms such as Proof of Work (PoW) or Proof of Stake (PoS)

Permissioned consensus suits:

National blockchains and large-scale data infrastructure
Public services, digital identity, and data verification
Enterprise networks requiring transparent governance and legal compliance
Systems needing high performance, accountability, and clearly identified validators

Choosing a consensus mechanism is therefore not about finding the "most decentralized" model, it is about selecting the architecture that best fits the operational objective. This is also the approach taken by many national blockchains today, including NDAChain, in prioritizing performance, governance, and digital trust for national-scale applications.

5. Why does the national blockchain platform choose permissioned consensus?

NDAChain is designed as national data infrastructure serving digital identity, data verification, and traceability. The platform therefore chooses permissioned consensus combined with the PoA-qBFT mechanism to meet the requirements of performance, governance, and data sovereignty at national scale.

Ensuring legal accountability: Validators are agencies, organizations, and enterprises with verified identities, legally accountable for data validation activities and network operations.
High performance and instant confirmation: NDAChain achieves processing capacity of 1,200–3,600 TPS with near-instant finality, suitable for large-scale digital services.
Protecting data sovereignty: The validator governance mechanism helps ensure that national data is operated on infrastructure owned by Vietnam, consistent with the direction of digital infrastructure development and data sovereignty.
Energy efficiency: No mining activity or computational competition is required, unlike public blockchains using Proof of Work (PoW).

It is worth noting that permissioned consensus does not mean centralization. Validation rights remain distributed across multiple independent validator nodes from both the public and private sectors, ensuring transparency, resistance to unilateral manipulation, and maintained accountability when needed.

6. Choosing a consensus model based on the national challenge

The reasoning behind why permissioned consensus is the top choice for national blockchain platforms

Permissioned consensus and public consensus are not two competing models searching for a "better" side, they are two approaches designed for different objectives. If public consensus lays the foundation for public blockchains and global digital asset ecosystems, then permissioned consensus is built to serve systems requiring high performance, transparent governance, legal compliance, and accountability.

Public consensus suits open environments where trust is formed through consensus mechanisms and economic incentives.

Permissioned consensus suits data infrastructure, public services, and networks requiring verified identities and clear legal accountability.

For a national blockchain, where citizen data, digital identity, and digital services serve as foundational elements the requirements of data sovereignty, transparency, and auditability are key factors. NDAChain therefore chooses permissioned consensus with PoA-qBFT as its core consensus foundation. This is not the optimal choice for every type of blockchain, it is the model best suited to Vietnam's objective of building national digital trust infrastructure.

Frequently asked questions about permissioned consensus and public consensus

How do permissioned consensus and public consensus differ?
The biggest difference lies in the right to participate in transaction validation. With public consensus, anyone meeting the technical requirements can become a validator or miner without prior authorization. With permissioned consensus, only organizations or entities with verified identities may participate in operating the network. Public consensus prioritizes maximum decentralization, while permissioned consensus focuses on performance, governance, and accountability.

What is public consensus?
Public consensus is the consensus model of open blockchains, where any individual or organization meeting technical requirements can participate in validating transactions without permission, validators are typically anonymous. The most common mechanisms are Bitcoin's Proof of Work and Ethereum's Proof of Stake. Trust comes from economic mechanisms such as computational cost or staked assets.

What is permissioned consensus?
Permissioned consensus is the consensus model of permissioned blockchains, where only approved and identity-verified entities may serve as validators, with the validator list governed by formal rules. Common mechanisms include Proof of Authority and BFT algorithms such as qBFT, achieving instant finality and high TPS. Trust comes from the reputation and legal accountability of validators.

Why does NDAChain choose permissioned consensus?
As national infrastructure, NDAChain chooses permissioned consensus with PoA-qBFT for legal accountability, each validator has a verified identity high performance of 1,200–3,600 TPS with instant finality, data sovereignty through control of the validator list, and energy efficiency without mining activity. NDAChain uses 49 public-private validators comprising government agencies and major corporations.

Is permissioned consensus the same as centralization?
No. In NDAChain, validation rights are distributed across 49 public-private validators that are independent agencies and organizations, sufficient to prevent unilateral manipulation, since no single party controls the network alone. Unlike public blockchains, validators have verified identities and are authorized, but rights are still distributed among multiple parties, making this governed decentralization rather than centralization.