Types of Blockchains Explained- Public Vs. Private Vs. Consortium

• Toshendra Kumar Sharma
• June 06, 2024

Did you know over 40 million people use the Blockchain technology around the world? Blockchain technology has rapidly evolved, becoming a buzzword in various industries. The global Blockchain market size is expected to grow from USD 92 billion in 2021 to USD 1,431.54 billion by 2030, at a CAGR of 9%. But are all Blockchains the same?

Understanding the different types of Blockchains is crucial in navigating the complex landscape of decentralized systems. Wondering what the different types of Blockchain are? Are you Juggling between public, private and federated Blockchains? In this article, we’ll break down the three main categories: Public, Private, and Consortium Blockchains. Whether you’re a newcomer or looking to deepen your knowledge, this guide aims to provide a clear and concise overview of these Blockchain variants and their distinct features. Let’s dive into the world of Blockchains and unravel the key differences between Public, Private, and Consortium Blockchains.

So let’s get started. 

Types of Blockchains Explained

Depending on the use and requirements, Blockchains have been categorized into three types, public, private, and consortium (also known as federated). Each of these Blockchain networks serves its purpose and solves particular problems, and each Blockchain has its own set of features and advantages over one another. Let’s start with the most commonly known Blockchain, i.e., public Blockchain.

Public Blockchain 

This Blockchain is a permissionless, non-restrictive, distributed ledger system, which means anyone who is connected to the internet can join a Blockchain network and become a part of it. The basic use of such Blockchain is for exchanging cryptocurrencies and mining. Moreover, it maintains trust among the whole community of users as everyone in the network feels incentivized to work towards the improvement of the public network. The first example of such a Blockchain is Bitcoin that enabled everyone to perform transactions. Litcoin, Solana, Avalanche and Ethereum are also examples of public Blockchains..

Merits:

• Decentralization: Public Blockchains operate on a decentralized network of nodes, making it resistant to censorship or control by a single entity. This ensures a more democratic and inclusive system.
• Transparency: All transactions on a public Blockchain are visible to anyone in the network. This transparency fosters trust among participants as they can verify transactions and the overall state of the network.
• Security: Public Blockchains often use consensus mechanisms like Proof of Work or Proof of Stake, making it extremely difficult for malicious actors to alter transaction history or compromise the security of the network.
• Immutability: Once a block is added to the Blockchain, it is practically impossible to alter its content. This immutability ensures the integrity of the transaction history and builds trust among users.
• Interoperability: Public Blockchains can be accessed and used by anyone, encouraging interoperability and collaboration across different platforms and applications. This openness promotes innovation and a wider range of use cases.
• Tokenization: Many public Blockchains support the creation of tokens. This allows for the representation of various assets on the Blockchain, enabling efficient and secure transfer of ownership.
• Community-driven Development: Public Blockchains often have a community of developers working on the improvement and maintenance of the network. This diverse and distributed development community contributes to the resilience and adaptability of the Blockchain.
• Global Accessibility: Public Blockchains are accessible to anyone with an internet connection, providing financial services and opportunities to individuals who may be excluded from traditional banking systems.
• Trustless Transactions: Participants in a public Blockchain do not need to trust each other. They can trust the underlying protocol and the consensus mechanism, which ensures the validity of transactions without the need for intermediaries.
• Incentive Mechanisms: Many public Blockchains use incentive mechanisms like token rewards to encourage participants (miners or validators) to contribute to the network’s security and functionality.

Demerits:

Scalability Issues:

• Problem: Public Blockchains can face challenges in handling a large number of transactions simultaneously.
• Impact: This can result in slower transaction processing times and higher fees during network congestion.

Energy Consumption:

• Problem: Proof-of-work consensus mechanisms, like in Bitcoin, require significant computational power, leading to high energy consumption.
• Impact: This not only raises environmental concerns but also makes the operation of the network expensive.

Privacy Concerns:

• Problem: Public Blockchains are transparent, and all transactions are visible to anyone.
• Impact: Lack of privacy can be a disadvantage for users who want to keep their financial activities confidential.

Regulatory Challenges:

• Problem: Governments and regulatory bodies may find it difficult to monitor and control activities on public Blockchains.
• Impact: This can lead to legal uncertainties, hindering broader adoption and acceptance.

Immutability Dilemma:

• Problem: The immutability of transactions, while a security feature, can become a problem in case of errors or fraudulent activities.
• Impact: Once a transaction is recorded, it cannot be easily altered, posing challenges in correcting mistakes.

Lack of Governance:

• Problem: Public Blockchains often lack formal governance structures.
• Impact: Decision-making processes and protocol upgrades may become contentious, potentially leading to forks and divisions in the community.

User-Friendly Challenges:

• Problem: Interacting with public Blockchains can be complex for non-technical users.
• Impact: This limits the widespread adoption of Blockchain technology as it requires a certain level of technical knowledge.

Transaction Costs:

• Problem: Public Blockchains may involve transaction fees, and these fees can be unpredictable.
• Impact: Users may find it challenging to estimate the cost of transactions accurately, leading to unpredictability in expenses.

Smart Contract Risks:

• Problem: While smart contracts are a powerful feature, they are not immune to bugs or vulnerabilities.
• Impact: Flaws in smart contracts can lead to significant financial losses and undermine trust in the platform. 

Private Blockchain 

Unlike the public, a private Blockchain is a permission and a restrictive Blockchain that operates in a closed network. Such Blockchain is mostly used within an organization where only particular members are participants of a Blockchain network. It is best suited for enterprises and businesses that want to use Blockchain only for internal uses. The major difference between the Blockchains is that the public is highly accessible, whereas private is confined to a particular group of people. Moreover, a private Blockchain is more centralized due to the fact that a single authority maintains the network. IBM, R3 Corda, Hyperledger Fabric, Hyperledger Sawtooth, etc. are the examples of private Blockchains.

Merits:

• Enhanced Privacy and Confidentiality: Private Blockchains restrict access to authorized participants, ensuring that sensitive information is not visible to the public. This is crucial for businesses and organizations that need to maintain confidentiality.
• Greater Control: Participants in a private Blockchain have more control over the consensus mechanism, governance, and overall rules of the network. This allows for quicker decision-making and adaptation to specific business requirements.
• Efficiency: Private Blockchains often have higher transaction throughput and faster confirmation times compared to public Blockchains. This efficiency is beneficial for businesses that require rapid and high-volume transactions.
• Reduced Energy Consumption: Some private Blockchains use consensus mechanisms that are less energy-intensive compared to the Proof of Work used by many public Blockchains. This can be an advantage for organizations aiming to minimize their environmental impact.
• Compliance with Regulations: Private Blockchains can be designed to comply with specific regulations and industry standards. This is crucial for businesses operating in highly regulated sectors, such as finance and healthcare, where strict adherence to rules is essential.
• Customization: Participants in a private Blockchain have the flexibility to customize the Blockchain according to their specific needs. This adaptability is valuable for businesses with unique requirements that may not be met by public Blockchains.
• Faster Adoption: Implementing a private Blockchain may be more palatable for traditional businesses as it allows them to experiment with Blockchain technology without fully exposing their operations to the public.
• Lower Transaction Costs: Since private Blockchains may have fewer participants and are often more efficient, transaction costs can be lower compared to public Blockchains, especially when dealing with a high volume of transactions.
• Scalability: Private Blockchains can be more easily scaled to meet the specific needs of a business or organization. This scalability is important for enterprises with growing transaction volumes.
• Integration with Existing Systems: Private Blockchains can be designed to seamlessly integrate with existing systems and databases. This integration facilitates a smoother transition for businesses incorporating Blockchain technology into their operations. 

Demerits:

Centralization Concerns:

• Problem: Private Blockchains are often more centralized, with a limited number of participants controlling the network.
• Impact: This undermines the decentralized nature that is a core principle of Blockchain technology, potentially leading to concentration of power.

Limited Transparency:

• Problem: Private Blockchains may restrict access to certain information, reducing the transparency compared to public Blockchains.
• Impact: Reduced transparency can be a drawback in scenarios where stakeholders require visibility into all transactions and activities.

Security Risks:

• Problem: The security of a private Blockchain heavily relies on the trustworthiness of the participating entities.
• Impact: If a participant is compromised or acts maliciously, it can jeopardize the overall security of the network.

Interoperability Challenges:

• Problem: Private Blockchains may face difficulties in interoperability with other Blockchain networks and systems.
• Impact: This lack of interoperability can hinder seamless communication and data exchange between different networks.

Dependency on a Single Entity:

• Problem: Private Blockchains often depend on a single organization or consortium to maintain and operate the network.
• Impact: If this central entity fails or faces issues, the entire Blockchain network may be at risk.

Incentive Structure Issues:

• Problem: Private Blockchains may struggle with creating effective incentive structures for participants.
• Impact: Without proper incentives, participants may lack motivation to contribute to the network’s security and maintenance.

Potential for Collusion:

• Problem: Since participants in private Blockchains are known entities, there is a risk of collusion.
• Impact: Collusion could lead to manipulative practices or biased decision-making within the network.

Costs and Resource Requirements:

• Problem: Setting up and maintaining a private Blockchain can be expensive, requiring significant resources.
• Impact: This cost factor may limit the accessibility of Blockchain technology, particularly for smaller organizations.

Limited Tokenization Opportunities:

• Problem: Private Blockchains may have limitations in creating and managing tokens or cryptocurrencies.
• Impact: This reduces the potential for developing and implementing tokenization-based applications and business models.

Governance Challenges:

• Problem: Governance in private Blockchains may be controlled by a select group, leading to potential conflicts of interest.
• Impact: Lack of inclusive governance may hinder decision-making processes and result in suboptimal outcomes for the network.

Consortium Blockchain

Consortium Blockchain (also called federated Blockchains) is best suited for organizations where there is a need for both types of Blockchains, i.e., public and private. In this type, there is more than one central in-charge, or we can say more than one organization involved who provides access to pre-selected nodes for reading, writing, and auditing the Blockchain. Since there is no single authority governing the control, it maintains decentralized nature. 

Contour, TradeLens, Energy Web Foundation, IBM Food Trust are examples of consortium Blockchain.

Merits:

• Shared Control: In a consortium Blockchain, multiple organizations or entities jointly control the network. This shared control fosters collaboration and allows for collective decision-making, making it suitable for industries where multiple stakeholders need to collaborate.
• Enhanced Privacy: While not as private as fully private Blockchains, consortium Blockchains still offer a higher level of privacy compared to public Blockchains. Participants have a degree of control over who can join the network, ensuring a level of confidentiality.
• Efficiency and Speed: Similar to private Blockchains, consortium Blockchains can offer higher efficiency and faster transaction processing compared to public Blockchains. This is particularly useful in scenarios where a moderate level of decentralization is desired without sacrificing performance.
• Cost Savings: By sharing the infrastructure and maintenance costs, participants in a consortium Blockchain can achieve cost savings compared to implementing a private Blockchain independently. This shared financial responsibility makes Blockchain technology more accessible to a broader range of organizations.
• Interoperability: Consortium Blockchains facilitate interoperability between different organizations within the network. This can streamline processes, improve communication, and create a more cohesive ecosystem among the consortium members.
• Customization and Flexibility: Similar to private Blockchains, consortium Blockchains allow for customization to meet the specific needs of the participants. This adaptability is valuable in industries with diverse requirements, such as supply chain management or healthcare.
• Trust among Participants: Consortium Blockchains leverage a shared and distributed ledger, promoting trust among participants. This trust is crucial for industries where transparency and accountability are essential, such as in supply chain traceability or collaborative research.
• Compliance with Regulations: Consortium Blockchains can be designed to comply with industry regulations, providing a balance between regulatory requirements and the benefits of Blockchain technology. This is particularly important in sectors with strict regulatory frameworks.
• Resilience: The shared control in consortium Blockchains enhances the resilience of the network. Even if one participant experiences issues, the overall integrity of the Blockchain can be maintained through the consensus of the remaining members.
• Gradual Adoption: Consortium Blockchains offer a middle ground for organizations looking to gradually adopt Blockchain technology. It allows them to collaborate with selected partners or stakeholders before considering a more open or fully private Blockchain solution.

Demerits:

Limited Decentralization:

• Problem: While more decentralized than private Blockchains, consortium Blockchains still involve a restricted group of participants.
• Impact: This can lead to concerns about the concentration of power among the participating entities, compromising the decentralization principle.

Complex Governance Structures:

• Problem: Consortium Blockchains often require complex governance structures to manage decision-making among the participating organizations.
• Impact: Developing and maintaining effective governance can be challenging, potentially leading to conflicts and delays in decision-making.

Interoperability Challenges:

• Problem: Similar to private Blockchains, consortium Blockchains may face difficulties in interoperability with other Blockchain networks.
• Impact: Limited interoperability can hinder the exchange of data and assets between different consortiums or networks.

Security Risks from Member Actions:

• Problem: The security of a consortium Blockchain relies on the trustworthiness of its members.
• Impact: If a member acts maliciously or is compromised, it can pose security risks to the entire network.

Scalability Issues:

• Problem: Consortium Blockchains might encounter scalability challenges, especially as the number of participants and transactions increases.
• Impact: This can result in slower transaction processing times and increased costs during periods of high activity.

Potential for Cartel-Like Behavior:

• Problem: Consortiums, being composed of a limited number of entities, may engage in cartel-like behavior.
• Impact: This behavior can lead to anti-competitive practices, undermining the principles of fairness and openness.

Incentive Structure Challenges:

• Problem: Designing effective incentive structures for participants in a consortium Blockchain can be complex.
• Impact: Without proper incentives, participants may lack motivation to contribute to the security and growth of the network.

Dependency on Key Members:

• Problem: The success of a consortium Blockchain may be heavily dependent on the active involvement of key member organizations.
• Impact: If key members withdraw or reduce their participation, it can impact the stability and viability of the entire consortium.

Complex Integration Processes:

• Problem: Integrating existing systems and processes into a consortium Blockchain can be challenging.
• Impact: The complexity of integration may slow down adoption and implementation, affecting the overall efficiency of the consortium.

Cost Sharing and Funding Issues:

• Problem: Allocating and sharing costs among consortium members can be a complex task.
• Impact: Disputes over financial matters may arise, potentially affecting the sustainability of the consortium.

Private Blockchain Vs. Public Blockchain Vs. Consortium Blockchain

Aspect	Private Blockchain	Public Blockchain	Consortium Blockchain
Access Control	Restricted access	Open to anyone	Limited access
Participants	Known and permissioned	Anonymous and open	Known and permissioned
Consensus Mechanism	Faster, less energy-intensive	Slower, energy-intensive	Variable, depends on consensus model
Decentralization	More centralized	Fully decentralized	Intermediate level
Speed and Scalability	Faster and scalable	Slower and less scalable	Moderate speed and scalability
Example	Hyperledger Fabric, Corda	Bitcoin, Ethereum	Quorum, R3 Corda

Access Control:

• Private Blockchain: Access is restricted to a specific group of participants who are typically known and permissioned by a central authority. This ensures a higher level of trust among participants. The permissioned nature allows for faster transactions and lower latency.
• Public Blockchain: Open to anyone without requiring permission. Participants can join the network pseudonymously, and transactions are validated by a consensus mechanism that doesn’t rely on trust among participants. This openness promotes decentralization but can lead to slower transaction speeds.
• Consortium Blockchain: Access is limited to a predefined group of participants. While not entirely open, it is more inclusive than a private Blockchain. The consortium determines and manages permissions, providing a balance between openness and control.

Participants:

• Private Blockchain: Participants are typically known entities, and their identities are often verified. This identity verification enhances trust and allows for more straightforward governance.
• Public Blockchain: Participants are pseudonymous, identified by cryptographic addresses. Anyone can participate, and trust is established through the consensus mechanism and the transparent nature of the Blockchain.
• Consortium Blockchain: Participants are known and permissioned by the consortium. Identity verification is maintained within the defined group, fostering a level of trust similar to private Blockchains.

Consensus Mechanism:

• Private Blockchain: Often employs faster, more efficient consensus mechanisms like Practical Byzantine Fault Tolerance (PBFT) or Raft. These mechanisms are suitable for a controlled environment with trusted participants.
• Public Blockchain: Relies on more time-consuming and energy-intensive consensus mechanisms such as Proof of Work (used by Bitcoin) or Proof of Stake (used by Ethereum). These mechanisms are designed to achieve decentralized consensus in an open network.
• Consortium Blockchain: The consensus mechanism can vary based on the specific needs and goals of the consortium. It may include a combination of mechanisms like PBFT, Proof of Authority (PoA), or other consensus models tailored to the consortium’s requirements.

Decentralization:

• Private Blockchain: More centralized, as control is often in the hands of a central authority or a limited number of trusted participants. While it offers efficiency, it sacrifices some aspects of decentralization.
• Public Blockchain: Fully decentralized, with no central authority. Decision-making and validation of transactions are distributed across a network of nodes, providing a high level of trust and censorship resistance.
• Consortium Blockchain: Provides an intermediate level of decentralization. Control is distributed among the consortium members, allowing for collaboration while maintaining some degree of centralized governance.

Speed and Scalability:

• Private Blockchain: Generally faster and more scalable due to the controlled and known participants. The limited number of nodes facilitates quicker consensus and validation.
• Public Blockchain: Slower and less scalable, especially as the number of participants increases. The decentralized nature introduces complexities in achieving consensus, leading to longer transaction times.
• Consortium Blockchain: Offers moderate speed and scalability. While not as fast as a private Blockchain, it can be more efficient than a fully public Blockchain, striking a balance between speed and decentralization.

Conclusion

To declare which Blockchain is best won’t be right because each Blockchain has its own features, advantages, usage, and requirements. If you are a part of a public Blockchain, then you should have an in-depth knowledge of it. But if you want to design and implement your own enterprise Blockchain, a private Blockchain is a one-stop solution in that case. Consortium Blockchain is likely to interest enterprises and organizations who want to efficiently streamline communication among one another. Before choosing a perfect Blockchain, don’t forget to reconsider your business requirements and features that each Blockchain offers. 

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Frequently Asked Questions

What are the 3 main types of Blockchains?

• Public Blockchain: Open and permissionless, allowing anyone connected to the internet to join, exemplified by Bitcoin and Ethereum.
• Private Blockchain: Restricted and operates within closed networks, typically used for internal organizational purposes, like Hyperledger Fabric and R3 Corda.
• Consortium Blockchain: Involves multiple organizations, providing access to pre-selected nodes, striking a balance between public and private Blockchains.

What is the most common type of Blockchain?

• The most common type of Blockchain is the Public Blockchain. 
• It is widely recognized, open to anyone, and exemplified by cryptocurrencies like Bitcoin and Ethereum.

What are the 3 most important components for a Blockchain?

• Decentralized Network: Operating without a central authority, ensuring a democratic and inclusive system.
• Consensus Mechanism: A method for nodes to agree on the state of the Blockchain, such as Proof of Work or Proof of Stake.
• Distributed Ledger: A ledger that is duplicated across the entire network, ensuring transparency and security.

What is the best type of Blockchain?

• Determining the “best” type of Blockchain depends on specific needs and use cases.
• Public Blockchains offer global accessibility, transparency, and trustless transactions but face challenges like scalability and energy consumption.
• Private Blockchains provide enhanced privacy, control, and efficiency but may have issues like centralization and limited transparency.
• Consortium Blockchains offer shared control, improved privacy, and efficiency, balancing characteristics of both public and private Blockchains.