Public, Private, and Permissioned Blockchains: A Comparison

You’ve probably heard a lot about blockchains with cryptocurrencies like Bitcoin and Ethereum using public blockchains. But blockchains have many more uses beyond just powering digital currencies. As the blockchain space matures, different blockchains have emerged to suit different needs.

In this article, we’ll break down the differences between public, private, and permissioned blockchains so you can better understand them.

Defining Public, Private and Permissioned Blockchains

Public blockchains are open, permissionless, and decentralized networks where anyone can participate. They offer transparency and security but lower efficiency and scalability.

Private Blockchains are closed networks where only approved nodes can join. They provide more control and efficiency but need more transparency and decentralization.

Permissioned blockchains sit in the middle. They have approved nodes but are open for anyone to join. They aim to balance privacy and transparency.

The Advantages of Public Blockchains

Public blockchains like Bitcoin and Ethereum offer appealing benefits over private or permissioned ones.

Typically, public blockchains are completely open and transparent. Anyone can join the network, access the ledger, and see the transaction history. This openness promotes trust and accountability since no single group controls the data.

Public blockchains are also highly secure and resistant to manipulation. Because thousands of nodes maintain the network, it’s nearly impossible for any single party to gain control or manipulate records. This makes public blockchains ideal for applications where transparency and security are priorities.

Another big plus of public blockchains is their decentralization. Records are distributed across numerous locations, so there’s no single point of failure. The network can continue operating as long as some nodes are online.

Of course, public blockchains aren’t for everyone. They typically have slower transaction speeds and higher costs compared to private alternatives. And since anyone can join, public blockchains may not meet regulatory privacy and data control requirements.

Public blockchains are the way to go if you value an open network where no one party is in control. With trade-offs considered, they offer benefits that private and permissioned blockchains can’t match.

The Benefits of Private Blockchains

Private Blockchains offer some unique benefits over public blockchains. 

They include:

Increased Privacy

Private Blockchains restrict access to authorized persons only. Transactions and data are visible only to approved users. On the other hand, public blockchains have open data that anyone can see. For businesses that value privacy, private blockchains are appealing. Sensitive information like financial transactions, trade secrets, or personal data can be kept confidential.

Higher Efficiency

Private Blockchains have lower latency and higher throughput since they have fewer nodes to reach consensus. They can also be customized to suit the organization’s needs. 

For example, block sizes and consensus mechanisms can be tailored to optimize speed and cost. In comparison, public blockchains have to cater for a diverse, global set of users, making it more difficult to scale.

Greater Control

With private blockchain, the founding organizations have more control over the network. They determine who can access the blockchain, what types of transactions are allowed, and how the network evolves. There is no risk other than uncontrolled change that can disrupt performance. Public blockchains, on the other hand, are decentralized and permissible. There is no one thing in control, so that communication patterns can be very chaotic and unpredictable.

Advantages of Permissioned Blockchains

Permissioned blockchains are ideal when restricting access and controlling who can join your network. Unlike public blockchains, where anyone can participate, permissioned blockchains require an invitation to join.

With a permissioned blockchain, you determine who can access the network and what level of permissions each participant has. They also give you more control over the network. You can decide who validates transactions, and you have governance over any changes made to the network.

Additionally, they have higher transaction speeds than public blockchains because fewer nodes process each transaction. With fewer participants validating transactions, consensus is reached faster. This makes permissioned blockchains better suited for high-volume transactions.

Which Blockchain Is Right for You? 

First, think about how you want to use the blockchain. A public blockchain is best for cryptocurrencies or other open networks. Private or permissioned blockchains are better for internal company data or supply chain management, where privacy and control are important.

Cost and flexibility are important factors to take into account. Public blockchains are often free to use but can be expensive to scale. Private and permissioned blockchains typically charge network fees to cover operating costs. 

You can customize the network and consensus rules to suit your needs. Public blockchains are more rigid since changing the rules would undermine security and decentralization.

Examining all of this will assist you in determining which type of blockchain is right for you. As the blockchain space evolves, watch for new developments and innovations.