Public vs Private Blockchains

Public vs Private Blockchains: A Head-to-Head Comparison

Public vs Private Blockchains

Blockchain technology has disruptive potential across many industries. However, not all blockchains are created equal. There are key differences between public and private blockchains that determine their use cases and implementation. Understanding these differences is critical for organizations exploring blockchain solutions.

What Are Public and Private Blockchains?

A blockchain is a distributed ledger technology (DLT) that allows parties to conduct secure transactions without needing a central authority. Participants maintain copies of the ledger, reaching a consensus to validate transactions.

Public blockchains are open networks that anyone can join. Transactions are visible to all participants. Bitcoin and Ethereum are leading public blockchain platforms. Their native cryptocurrencies promote network participation through rewards.

In contrast, private blockchains restrict access and keep transactions private. Only authorized nodes can participate based on rules set by the network starter. Private blockchains are popular for enterprise use cases that demand privacy.

Key Differences Between Public and Private Blockchains

While both utilize DLT, public and private blockchains differ significantly:

Consensus Mechanisms

Public blockchains typically use proof-of-work or proof-of-stake to validate transactions. These incentives encourage distributed participation. Private blockchains can use more efficient consensus models like proof-of-authority since nodes are permissioned.


Public blockchains can have scalability issues with increased use. Private blockchains easily scale by limiting access. Performance also improves by restricting participation.


Anyone can access, view, or submit transactions on public blockchains. Private blockchains limit roles and permissions to specific entities. This increased control enables better privacy.

Security Models

The openness of permissionless blockchains makes them more prone to 51% attacks. Private chains offer greater protection as validators are vetted and known. However centralized authority creates trust issues regarding collusion.


Changes to public blockchains require community consensus regarding technical upgrades. Private blockchains follow leadership from the organization managing the network.

Use Cases

Public blockchains suit solutions like cryptocurrencies, DeFi platforms, and NFT marketplaces. Private chains better serve centralized entities’ needs across finances, logistics, and healthcare.

Public vs Private Blockchain Comparison

ParameterPublic BlockchainsPrivate Blockchains
Consensus ApproachPermissionless; Proof-of-Work/Stake algorithmsPermissioned; Multiple consensus models
ScalabilityLimited, several transactions per secondPermissions; Multiple consensus models
AccessibilityOpen to anyone globallyRestricted access to authorized entities
SecurityProne to 51% attacks due to opennessEnhanced security as validators are known
GovernanceDecentralized, requires consensus across nodesCentralized based on the managing entity
Use CasesCryptocurrencies, DeFi, NFT MarketplacesHigh through permissions
Public vs Private Blockchain Comparison

This table summarizes how public versus private blockchains differ. Their unique attributes make them suitable for certain applications.


Public blockchains prioritize decentralization and accessibility. Private chains emphasize scalability, security, and control. While their core principles vary, both DLT models drive innovation.

Understanding the key differences between them in terms of consensus, access, security, upgrades, and use cases is vital for success. Assessing your specific requirements will clarify which approach serves your needs better.

With their complementary strengths, public and private blockchains can together accelerate a blockchain-powered future across industries.

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