The 6 Types of Blockchain Technology Explained Simply

Published: 6th July, 2024 | Last Updated: 1st July, 2024

Markos Koemtzopoulos

Markos Koemtzopoulos is the founder and main writer of ElementalCrypto. He has been a lecturer at the University of Nicosia on cryptocurrencies and DeFi and has taught two courses on crypto and blockchain technology.

In this post, I will explain the 6 main types of blockchain technology. 

Blockchains can be classified into several types based on their structure, access permissions, and use cases. 

Here are the primary categories:

  1. Public Blockchains
  2. Private Blockchains
  3. Consortium Networks (Federated Blockchains)
  4. Hybrid Blockchains
  5. Sidechains
  6. Layer 2 Solutions

Six Different Types of Blockchain

Illustration of Cryptocurrency Blockchain

1. Public Blockchains

A Public blockchain network is a decentralized digital ledger that is open to everyone. They operate on a permissionless model, meaning anyone with an internet connection can join the network, participate in the consensus process (validating and verifying transactions), and access the blockchain’s data. This openness ensures trustless and transparent systems without a central authority.

Examples:

  • Bitcoin: Bitcoin is the first and most well-known public blockchain, and it is primarily used for peer-to-peer digital currency transactions.
  • Ethereum: A public blockchain that supports the creation of tokens and decentralized applications (DApps) through smart contracts.

Characteristics:

  1. Decentralized:
    • No Central Authority: Public blockchains are maintained by a distributed network of nodes (computers) rather than a single central entity. This decentralization ensures that no single party can control or manipulate the blockchain.
    • Peer-to-Peer Network: Transactions are directly conducted between participants without intermediaries, reducing the risk of censorship and enhancing transaction speed and efficiency. Anyone can send a message and sign it to prove it was them sending the message. Network participants can then verify the message. 
  2. Transparent:
    • Open Ledger: All transactions are recorded on a public ledger that is accessible to anyone. This transparency ensures that all participants can independently verify and audit the blockchain’s data.
    • Immutable ledger: Once data is added to the blockchain, it cannot be altered or deleted. This ensures historical data remains unchanged.
  3. Secure Through Consensus Mechanisms:
    • Proof of Work (PoW): Used by Bitcoin, the PoW consensus algorithm requires network participants (miners) to solve complex mathematical problems, validate transactions, and add them to the blockchain. This process consumes significant computational power and energy but ensures high security and resistance to attacks.
    • Proof of Stake (PoS): Used by Ethereum 2.0 and other blockchains, PoS requires participants (validators) to lock up a certain amount of cryptocurrency as a stake. Validators are chosen to create new blocks and confirm transactions based on the amount of stake they hold and other factors. PoS is more energy-efficient than PoW and promotes greater decentralization by lowering the barrier to entry for validators.

Advantages of Public Blockchains:

  • Censorship Resistance: public blockchains are resistant to censorship by any single authority, ensuring that transactions and data remain accessible.
  • Global Participation: Anyone around the world can participate in the network. This fosters innovation and diverse applications.
  • Security: The large network of computers and the consensus mechanisms used in public blockchains make them highly secure against attacks such as double-spending and fraud.
  • Trustless Environment: Participants do not need to trust each other or any central authority because the blockchain protocol ensures trust through cryptographic proofs and consensus.

Challenges of Public Blockchains:

  • Scalability: Public blockchains often face scalability issues due to the need for all nodes to process and validate each transaction. This can lead to slower transaction times and higher fees during periods of high network activity.
  • Energy Consumption: Consensus mechanisms like PoW are energy-intensive, raising concerns about their environmental impact. However, Bitcoin, which is the biggest culprit, uses 50% of its energy from renewable energy sources.
  • Privacy: The transparency of public blockchains can be a double-edged sword, as it may not be suitable for applications requiring privacy and confidentiality of data.

2. Private Blockchains

Private blockchains are decentralized ledgers with restricted access. Participation is limited to a predefined group of participants. 

Unlike public blockchains, private blockchains operate under a permissioned model. 

This means that access to the private network, participation in the consensus process, and the ability to read or write transactions are controlled by a central authority or a consortium of organizations. 

A private blockchain network is usually tailored for enterprise use, focusing on privacy, security, and performance.

Examples:

  • Hyperledger Fabric: An open-source blockchain framework developed by the Linux Foundation, designed for use in enterprise contexts with a modular architecture, allowing customization of consensus mechanisms and access control.
  • R3 Corda: A blockchain platform developed by the R3 consortium, optimized for industries requiring complex transaction and contract management, such as financial services.

Characteristics:

  1. Controlled Access:
    • Permissioned Network: Participation in a private blockchain is restricted to authorized users. Only verified participants can join the network, and they can only perform the actions that their permissions allow them to do.
    • Centralized Governance: A central authority or a consortium manages the network, setting rules and policies, granting permissions, and overseeing the overall operation of the blockchain.
  2. Faster Transaction Speeds:
    • Limited Participants: Fewer nodes need to validate transactions, leading to quicker consensus and faster transaction processing.
    • Optimized Consensus Mechanisms: Private blockchains can use less resource-intensive consensus algorithms (such as Practical Byzantine Fault Tolerance (PBFT) or Raft) tailored for speed and efficiency.
  3. Enterprise Applications:
    • Security and Efficiency: Private blockchains are designed for security and efficiency. They offer robust access controls, data privacy, and high throughput, making them suitable for various business applications.
    • Compliance and Regulation: Private blockchains can be configured to comply with industry regulations and standards.

Advantages of Private Blockchains:

  • Privacy: Only authorized participants can access the data
  • Scalability: With fewer participants and optimized consensus mechanisms, private blockchains can handle a higher volume of transactions
  • Customizability: Private blockchains can be tailored to meet the specific needs of an organization, including custom consensus algorithms, permission models, and governance structures.
  • Cost Efficiency: By reducing the need for computationally expensive consensus mechanisms and handling fewer transactions, private blockchains can be more cost-effective than public blockchains.

Challenges of Private Blockchains:

  • Centralization Risks: The presence of a central authority introduces risks such as single points of failure and potential misuse of power.
  • Limited Transparency: Restricted means reduced transparency, as only authorized participants can view transactions.
  • Interoperability: Ensuring interoperability with legacy systems can be challenging, potentially limiting their integration and adoption.

Use Cases for Private Blockchains:

  • Supply Chain Management: Track and verify the provenance of goods and streamline operations.
  • Financial Services: Facilitate secure, efficient, and transparent transactions, manage complex financial contracts, and comply with regulatory requirements.
  • Healthcare: Securely manage patient records, streamline medical billing, and enhance the privacy and integrity of healthcare data.
  • Corporate Governance: Enhance accountability in corporate governance, streamline voting processes, and ensure secure management of shareholder agreements.

3. Consortium Blockchains (Federated Blockchains)

Illustration of Blockchain

Consortium blockchains, also known as federated blockchains, are a type of permissioned blockchain where the consensus process is controlled by a pre-selected group of nodes representing different organizations. 

This semi-decentralized approach ensures that no single entity has full control over the blockchain. 

This fosters collaboration while maintaining a level of decentralization. 

Consortium blockchains are particularly well-suited for industries where multiple entities need to collaborate and share information securely and efficiently.

Examples:

  • Quorum: Developed by J.P. Morgan, Quorum is an enterprise-focused version of Ethereum designed for use in consortium settings, offering features like transaction and contract privacy.
  • Energy Web Foundation: A consortium blockchain aimed at accelerating the transition to a decentralized, democratized energy system.

Characteristics:

  1. Shared Control Among a Group:
    • Decentralized Governance: Unlike private blockchains, consortium blockchains distribute control across multiple organizations, reducing the risk of centralization and single points of failure. Decisions about the network are made collectively by the members.
    • Collaborative Framework: Organizations within the consortium can work together, sharing resources, data, and infrastructure to achieve common goals.
  2. Enhanced Security Compared to Public Blockchains:
    • Permissioned Access: Only vetted entities can join the network and validate transactions. 
    • Robust Consensus Mechanisms: Often use consensus algorithms that are more efficient and less resource-intensive.
  3. More Efficient Than Public Blockchains but Still Decentralized:
    • Improved performance with higher transaction throughput and lower latency.
    • Balanced decentralization means they still offer a level of decentralization that prevents any single entity from having undue influence over the network.

Advantages of Consortium Blockchains:

  • Inter-Organizational Collaboration: Consortium blockchains facilitate collaboration, allowing organizations to share information and transact without a central intermediary.
  • Cost and Resource Sharing: By pooling resources and infrastructure, consortium members can reduce costs and achieve economies of scale.
  • Regulatory Compliance as they comply with industry-specific regulations and standards.
  • Enhanced privacy: private transaction data can be kept confidential from non-participants

Challenges of Consortium Blockchains:

  • Complex governance: requires coordination and agreement among multiple organizations.
  • Interoperability Issues: Ensuring interoperability with other blockchain networks and legacy systems can be challenging,
  • Potential for Disputes: Disagreements among consortium members regarding governance, data sharing, and network operations can arise.

Use Cases for Consortium Blockchains:

  • Supply Chain Management: Enhance transparency and traceability in supply chains by allowing multiple stakeholders (manufacturers, suppliers, logistics providers, and retailers) to securely share information and track the movement of goods.
  • Finance and Banking: Facilitate secure inter-bank transactions, streamline trade finance processes, and enable cross-border payments while complying with regulatory requirements.
  • Healthcare: Enable secure sharing of patient data, streamline clinical trials, and ensure the integrity and confidentiality of medical records across different healthcare providers.
  • Energy Sector: Manage and optimize energy grids, facilitate peer-to-peer energy trading, and support the integration of renewable energy sources through collaboration among energy producers, distributors, and consumers.

4. Hybrid Blockchains

Illustration of Cryptocurrency

Hybrid blockchains are innovative systems that integrate features from both public and private blockchains to leverage the benefits of both. They allow for controlled access to certain data and operations while still enabling public interaction when necessary. This dual approach makes hybrid blockchains highly adaptable, providing the transparency and openness of public blockchains along with the privacy and control of private blockchains.

Examples:

  • Dragonchain: Originally developed by Disney, Dragonchain provides a hybrid blockchain platform that allows businesses to keep sensitive business logic private while leveraging the security of public blockchains.
  • XinFin: XinFin (XDC Network) is designed for international trade and finance, combining the benefits of public and private blockchains to facilitate secure and efficient transactions while maintaining regulatory Compliance.

Characteristics:

  1. Flexible Access Controls:
    • Permissioned and Permissionless Features: Hybrid blockchains can designate which parts of the blockchain are open to public access and which parts require permission. This flexibility allows for customizable access control tailored to specific use cases.
    • Role-Based Access: Different roles can be assigned to participants, each with distinct permissions, ensuring that only authorized individuals can access sensitive data or perform certain operations.
  2. Balance Between Transparency and Privacy:
    • Selective Transparency: Hybrid blockchains can make certain data publicly accessible for transparency and auditability while keeping other data private and accessible only to authorized parties. This selective transparency is crucial for businesses that need to comply with privacy regulations while maintaining trust with stakeholders.
    • Data Segmentation: Sensitive data can be stored in the private segment of the blockchain, while non-sensitive data can be stored in the public segment.

Advantages of Hybrid Blockchains:

  • Customization
  • Scalability
  • Security
  • Cost-Effectiveness

Challenges of Hybrid Blockchains:

  • Implementing a hybrid blockchain can be complex.
  • Ensuring interoperability between the public and private segments can be challenging
  • Establishing governance frameworks to manage the interactions and permissions between public and private participants can be difficult.

Use Cases for Hybrid Blockchains:

  • Supply Chain Management: Track and verify the provenance of goods publicly while keeping sensitive supplier information private.
  • Healthcare: Manage patient records with privacy, allowing public access to anonymized health data for research.
  • Finance: Facilitate secure, transparent financial transactions that need to be publicly auditable while keeping customer details private.
  • Public Services: Government agencies can use hybrid blockchains to provide transparency in public records and services while protecting citizens’ personal data.

5. Sidechains

Sidechains are independent blockchains that run in parallel to a main parent blockchain. 

By allowing transactions and computations to be processed on the sidechain, sidechains help alleviate congestion on the main chain. 

They might also provide additional features or capabilities that the main chain may not support.

Examples:

  • Liquid Network: Developed by Blockstream, Liquid Network is a sidechain of Bitcoin designed to facilitate faster and more confidential transactions for trading platforms, exchanges, and financial institutions.
  • Rootstock (RSK): RSK is a smart contract platform that operates as a sidechain to Bitcoin, enabling the execution of Ethereum-compatible smart contracts using Bitcoin as the underlying currency.

Characteristics:

  1. Interoperability with the Main Blockchain:
    • Two-Way Peg: Sidechains use a two-way peg mechanism to enable the transfer of assets between the main chain and the sidechain. This allows users to move tokens back and forth at a fixed exchange rate.
    • Cross-Chain Communication: Sidechains are designed to communicate and interact with the main blockchain seamlessly. This interoperability ensures that assets and data can flow between the chains without friction.
  2. Offload Transactions from the Main Chain to Reduce Congestion:
    • Scalability: By processing transactions on the sidechain, the main chain can handle a higher volume of transactions. This reduces congestion and lowers transaction fees.
    • Specialized Transactions: Sidechains can be optimized for microtransactions, complex smart contracts, or high-frequency trading, further enhancing performance.

Advantages of Sidechains:

  • Sidechains can provide additional functionalities, such as advanced smart contract capabilities or new token standards.
  • Sidechains help to reduce the load on the main chain
  • Developers test new features on sidechains first
  • Sidechains enhance the interoperability of different blockchain networks

Challenges of Sidechains:

  • They pause a security risk, especially if the consensus mechanism or peg mechanism is not robust
  • Implementing and maintaining a sidechain requires significant technical expertise and resources. 
  • The transfer of assets between the main chain and the sidechain can lead to liquidity issues.

Use Cases for Sidechains:

  • Faster and more confidential financial transactions, such as settlements, trading, and cross-border payments
  • Blockchain-based games often use sidechains to handle in-game transactions more scalably
  • Sidechains can track and verify the provenance and movement of goods in a supply chain

6. Layer 2 Solutions

Blockchain System

Layer 2 solutions are protocols built on top of an existing blockchain (referred to as Layer 1) to enhance its scalability and efficiency. 

Similar to sidechains, these solutions handle transactions off the main blockchain. However, in contrast to sidechains, layer two solutions still leverage the security and decentralization of the underlying Layer 1 blockchain. 

By offloading the processing of transactions to a secondary layer, Layer 2 solutions aim to reduce congestion, lower transaction fees, and increase transaction speeds on the main blockchain.

Examples:

  • Lightning Network (Bitcoin): A Layer 2 payment protocol that enables fast, low-cost transactions between participating nodes using off-chain transaction channels.
  • Plasma (Ethereum): A framework for building scalable applications on Ethereum by creating child chains that operate autonomously while periodically committing to the main Ethereum blockchain.

Characteristics:

  1. Enhanced Scalability:
    • Off-Chain Processing: Layer 2 solutions process transactions off the main blockchain, significantly reducing the number of transactions that need to be recorded on Layer 1. 
    • Transaction Batching: Multiple transactions can be bundled into a single transaction before being recorded on the main blockchain.
  2. Reduced Transaction Fees:
    • By processing transactions off-chain, Layer 2 solutions can significantly reduce transaction fees compared to Layer 1,
    • Lower fees enable the feasibility of microtransactions.
  3. Quick Transaction Processing:
    • L2s provide near-instant transaction confirmation times,

Advantages of Layer 2 Solutions:

  • Scalability
  • Cost Efficiency
  • Improved User Experience
  • Security

Challenges of Layer 2 Solutions:

  • It can be technically complex to implement
  • It might introduce new vulnerabilities
  • Achieving widespread adoption requires user-friendly interfaces and takes time

Use Cases for Layer 2 Solutions:

  • Payment Networks: Layer 2 solutions like the Lightning Network enable fast and low-cost payments
  • Decentralized Exchanges (DEXs): Layer 2 solutions can facilitate high-frequency trading and instant settlements on decentralized exchanges
  • Gaming and NFTs: Layer 2 solutions allow for the seamless execution of in-game transactions and the transfer of non-fungible tokens (NFTs) without the high costs and delays associated with Layer 1 transactions.
  • IoT and Smart Devices: Layer 2 solutions can support the high volume of small, frequent transactions generated by Internet of Things (IoT) devices.

Examples in Detail:

  • Lightning Network (Bitcoin):
    • How It Works: The Lightning Network uses payment channels that allow users to transact off-chain. Two parties open a channel by committing funds to a multi-signature address on the Bitcoin blockchain. They can then make unlimited transactions between them off-chain, with only the opening and closing balances recorded on Layer 1.
    • Benefits: This reduces the load on the Bitcoin network, lowers transaction fees, and enables instant payments, making Bitcoin more practical for everyday use.
  • Plasma (Ethereum):
    • How It Works: Plasma creates child chains that can operate independently from the main Ethereum chain but periodically submit snapshots or checkpoints to the main chain for security. Each child chain can process transactions and smart contracts, offloading work from the main Ethereum blockchain.
    • Benefits: Plasma enhances Ethereum’s scalability by allowing complex computations and large volumes of transactions to be processed off-chain, reducing congestion and fees on the main chain.

Also, see the difference between crypto and bitcoin.

Markos Koemtzopoulos is the founder and main writer of ElementalCrypto. He has been a lecturer at the University of Nicosia on cryptocurrencies and DeFi and has taught two courses on crypto and blockchain technology.

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