What is the difference between public and private blockchains?


In recent years, the world has witnessed an increasing interest in blockchain technology. But what exactly is a blockchain, and why are there different types? In this article, we’ll explore the fundamental differences between public and private blockchains, their characteristics, use cases, and the advantages and disadvantages of each. So, let’s dive right in!

Understanding Blockchain Technology

Blockchain Basics

A blockchain is a decentralized, distributed ledger technology that records transactions across a network of computers. Each block in the chain contains a list of transactions, and once added, they’re nearly impossible to modify. This tamper-proof nature of blockchain technology makes it highly secure and transparent.

Types of Blockchains

There are primarily two types of blockchains: public and private. Both serve different purposes and have distinct characteristics. Let’s examine each type in detail.

Public Blockchains

Public blockchains are open, decentralized networks that allow anyone to join and participate in the network. They rely on a consensus mechanism, such as Proof of Work (PoW) or Proof of Stake (PoS), to validate transactions and maintain the integrity of the network.

Characteristics of Public Blockchains


In a public blockchain, there is no central authority controlling the network. Decentralization ensures that no single entity can manipulate the data or control the transactions.

Security and Transparency

Public blockchains use cryptographic techniques to ensure data security and transparency. Every transaction is visible to all network participants, making it difficult to alter or manipulate the data.

Open Participation

Anyone can join a public blockchain network, participate in the consensus process, and validate transactions. This openness fosters innovation and encourages the development of new applications.

Private Blockchains

Private blockchains, also known as permissioned blockchains, are controlled by a single organization or a group of organizations. Access to the network is restricted, and only authorized participants can validate transactions.

Characteristics of Private Blockchains

Centralized Control

Unlike public blockchains, private blockchains are controlled by a central authority. This authority manages the network, validates transactions, and grants permissions to participants.

Privacy and Confidentiality

Private blockchains prioritize privacy and confidentiality. Transactions are visible only to authorized participants, ensuring sensitive information remains secure.

Restricted Participation

In private blockchains, participants must receive an invitation or permission from the network’s controlling authority. This restricted access ensures that only trusted entities can join the network.

Comparing Public and Private Blockchains

Use Cases

Public Blockchain Use Cases

Public blockchains are often used for applications that require decentralization, security, and transparency. Some common use cases include:

  1. Cryptocurrencies like Bitcoin and Ethereum
  2. Decentralized finance (DeFi) platforms
  3. Supply chain traceability
  4. Voting systems
  5. Decentralized identity management

Private Blockchain Use Cases

Private blockchains are suitable for applications that require controlled access, privacy, and efficient transaction processing. Some common use cases include:

  1. Interbank transactions and settlement
  2. Supply chain management within a single organization or a consortium of organizations
  3. Asset tracking and management
  4. Secure sharing of medical records
  5. Corporate governance and compliance

Pros and Cons

Advantages and Disadvantages of Public Blockchains


  1. High level of security and transparency
  2. Decentralization prevents manipulation by a single entity
  3. Open participation encourages innovation


  1. Scalability issues due to the consensus mechanism
  2. High energy consumption in Proof of Work-based blockchains
  3. Slower transaction processing times

Advantages and Disadvantages of Private Blockchains


  1. Faster transaction processing times
  2. Enhanced privacy and confidentiality
  3. Controlled access reduces the risk of malicious actors


  1. Centralized control may lead to manipulation or single points of failure
  2. Limited innovation due to restricted participation
  3. Potential trust issues among participants


In summary, public and private blockchains serve different purposes and have unique characteristics. Public blockchains prioritize decentralization, security, and transparency, while private blockchains focus on privacy, confidentiality, and controlled access. Understanding the differences between these two types of blockchains can help you make informed decisions when selecting the right solution for your specific use case.


Is one type of blockchain better than the other?

It depends on your specific use case and requirements. Public blockchains are better for applications that require decentralization and transparency, while private blockchains are more suitable for applications that prioritize privacy and controlled access.

Can public and private blockchains be combined?

Yes, hybrid blockchains can combine the features of both public and private blockchains, allowing organizations to leverage the best of both worlds.

Are all cryptocurrencies built on public blockchains?

Most cryptocurrencies are built on public blockchains, but some are built on private or hybrid blockchains.

What is a consortium blockchain?

A consortium blockchain is a type of private blockchain where multiple organizations share control of the network, distributing trust and decision-making among them.

Can anyone see the transactions on a private blockchain?

No, only authorized participants can view transactions on a private blockchain, ensuring privacy and confidentiality.

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