Blockchain is too vague of a term that often hides many variants of how this technology can be implemented. Different protocols can differ depending on who can join its network, how accessible it is, and the degree of control and permissions involved. Public blockchains, in particular, break down barriers by offering unrestricted access to anyone interested in using the technology.
Let’s clarify the distinction between public vs private blockchains in this edition of our blog and bring some clarity into many terms floating around the decentralized space.
What is a Public Blockchain?
A blockchain is a special type of database that records not only the current state of the data but also all past states of that data from the very beginning. How this data is accessed defines whether the network is permissionless or private.
A public chain is a type of network that is accessible to all. This means that anyone can use it, view its data, developers can openly contribute, and, more importantly, anyone can volunteer and participate in the consensus process (e.g., mining or validating transactions).
Satoshi Nakamoto's implementation of Bitcoin was the first successful example of this type, demonstrating how such a system could operate securely and transparently without control from a centralized entity.
Today the majority of networks operate using this framework. Some very well-known public blockchain examples will include:
- Ethereum
- Solana
- BNB Smart Chain
- TON
- Cardano
N.B.: Still struggling to differentiate blockchains from cryptocurrencies? Check out our comparative guide.
How Public Blockchains Work
A traditional cryptocurrency network is characterized by non-permissioned functioning, that requires the following elements:
Instead of storing information on one server, the data structured in blocks is simultaneously stored across a distributed network of nodes;
Since there is no central authority controlling the network, a public chain uses consensus algorithms, such as Proof of Work (PoW) or Proof of Stake (PoS), that set in code how nodes should agree or disagree on data validity;
This system maintains a clear and chronological record of all activities. Once added to the blockchain, information cannot be erased, replaced, or edited – only appended with new data.
But what makes a crypto network truly permissionless is that anyone can download software that is required to run a node, synchronize it with all of the blockchain’s data, and become part of the system. All nodes in such type of network have equal rights to perform operations.
Characteristics of Public Blockchains
Blockchains like Bitcoin are often described as decentralized, trustless systems. Let’s decode what this characterization means exactly:
Open-source nature: Communities and developers are welcome to contribute to the continuous improvement and diversification of blockchain platforms;
Inclusivity: They are accessible from any computer, laptop, or mobile device. Users are immediately able to make transactions or, if they want, can configure their hardware to become node operators;
Independence: If public blockchain companies that initiated them cease to exist, these networks can continue to operate relying solely on nodes. One example is the Ethereum Classic chain that split its ways with the Ethereum Foundation and operates on tis own to this day.
This openness and lack of restrictive barriers allow drawing a clear contrast with other types of chains.
Benefits and Advantages of Public Blockchains
Everyone's welcome in open-access blockchains, but what makes these networks so trustworthy and reliable are their core advantages:
Redundancy of data: Hundreds, thousands, or potentially millions of copies of the same data stored across all of the nodes in the network increases the assurance level of the network;
Security: This distributed nature makes it hard to attempt and falsify any data;
High visibility: Any transactions put on the chain will be viewable. All participants can independently verify the data via explorers or by directly requesting information from the node.
Source: GetBlock
When we compare these to what private or permissioned networks offer, we can better understand why open-access blockchains have their own unique strengths. Let's address this comparison further.
Public vs. Private Blockchains
Opposite of a publicly accessible chain is a private blockchain, where participation and access are controlled and limited to specific authorized individuals or entities.
This allows for more control over who can read and write data to the blockchain, which can be beneficial for specific cases that require privacy and regulatory compliance.
However, this also means they do not offer the same level of decentralization and accountability — one of the advantages of public blockchain.
More key distinctions are explored in the table below.
| Feature | Public | Private |
|---|---|---|
| Control | No centralized management | Centralized; controlled by an entity |
| Access | Open to anyone | Closed for unauthorized users |
| Source Code | Open source | Unviewable, Closed development |
| Trust Mechanism | Consensus algorithms | Limited access |
| Privacy | User identity protected | Identifiable participants |
| Advantages | Inclusivity, independence, transparency, trust | Access control, performance, customizability |
| Trade-offs | Performance, scalability | Censorship risks, limited auditablitilty |
| Use Cases | Digital assets, dApps, DeFi, P2P transactions | B2B applications, internal business process management |
| Examples | Ethereum, Bitcoin, Solana, Cardano, BSC, TON | Hyperledger, Corda, Enterprise Ethereum |
While there are benefits and drawbacks to any of these systems, some organizations lean towards hybrid chains, combining the two architectures in order to pick the best elements of both.
Challenges and Limitations of Public Blockchains
Despite the benefits and advantages, open-access blockchains do face some hurdles. Yet, these aren't just drawbacks—they're opportunities for improvement. Let's take a closer look.
Speed
Decentralized networks can be slow due to computational resources and time required to reach an agreement among a large number of nodes, particularly as they scale up in size and user base. These challenges are being overcome with different solutions such as sharding and Layer-2 networks.
Privacy
Although crypto networks don't directly expose the personal identities of users, associated transactions remain fully visible. Therefore, additional information or analysis could potentially link activity to individuals.
On a side note, there are some proposed to solutions to solve the issue. Zero Knowledge-based technology is one of the examples of how private but transparently verifiable transactions can be implemented.
Onboarding challenges
While majority of blockchains are open and accessible, for businesses and startups intending to adopt the technology, the process is often associated with high infrastructure setup and maintenance costs.
Working with blockchain and crypto still requires specialized knowledge and expertise, yet, configuring the necessary hardware and software components is already facilitated by node providers. They significantly remove the barriers to entry for developers and companies.
Curious about how these services operate? Sign up to GetBlock now and explore immediate access to 50+ blockchains with a free plan.
Summing Up
The inclusive nature of public crypto networks undoubtedly drives the development of a new and promising technology which is blockchain. Guided by existing challenges, the capabilities of cryptocurrency networks we know will only grow and lead to a stronger ecosystem that more people use.
