Permissioned and Permissionless Blockchains: Structural Comparison

Introduction

Hardly can any innovation surpass the utility of blockchain technology in recent times. Its greatness lies in its revolutionary concept of decentralization and transparency. A common misunderstanding is that blockchain technology has no other use than that in cryptocurrencies, but this is only partial truth. All cryptocurrencies undoubtedly exist on one blockchain or the other, individuals and organizations have started using the technology for various other purposes than digital currencies. This article shed some useful light on two distinct types of blockchains, one of which is mostly used for non-financial purposes.

What are Permissionless Blockchains?

Anyone who has even some rudimentary knowledge about blockchain technology knows a few fundamentals of blockchain technology. A blockchain is a digital ledger that contains encrypted data in the form of blocks. A blockchain network contains a series of such blocks arranged chronologically so that every block contains information about the preceding block in such a way that no one can alter it. If someone tries to alter the block data or attempts to enter malicious elements, all participants can see it and validating nodes reject it through a consensus mechanism.

Consensus mechanism is key to understanding a permissionless blockchain. The type of blockchain that allows anyone to participate in verification of transactions and thus addition of new blocks is called a permissionless blockchain. Bitcoin, Ethereum, Solana, Cardano, BNB chain are all prominent examples of permissionless blockchains. It is safe to assert that the vast majority of crypto blockchains are permissionless.

What are Permissioned Blockchains?

A permissioned blockchain is kind of blockchain in which participation in consensus mechanism is limited to authorized members. For example, an organization wants to make all its decisions transparent. It creates a blockchain where everyone can see what is going on at the institutional level, yet new decisions are in the hands of those few who are at the helm of affairs. You can also think of it as a meeting in which everyone can enter the hall and listen, but only selected few can vote on key decisions. Many institutions such as banks, supply-chain companies and even government departments have started using this kind of blockchain as it provides the benefits of the technology without losing grip over internal protocols.

Advantages of Permissioned Blockchain

1. Efficiency

Since only a limited number of nodes participate in consensus mechanism, the network never becomes congested. Transactions are verified faster and blocks are added quickly. It will not be an overstatement if we say that a permissioned blockchain combines decentralization with some discipline.

2. Scalability

A permissioned blockchain is typically run by an entity with some degree of control over validators. Upgrades can therefore be implemented fairly easily.

3. Data Privacy and Customization

Many industries handle sensitive information like medical records, financial details, research data, or confidential contracts. They want their network to be unalterable, and at the same time, cannot risk exposing everything to the outside world. The option of customization allows developers to make changes as needs arise.

4. Controlled Degree of Transparency

In a permissioned blockchain, the owner of the network decides who can see the data and who can make changes. They can make the system more open or more private, depending on their needs. They can also control exactly who can and who cannot participate in the blockchain.

5. The Structure of Governance

Any change proposed in the blockchains like Bitcoin, Ethereum, etc. takes time in taking effect. Developers put forward a proposition and community may agree or disagree. On the other hand, permissioned blockchains may experience abrupt changes as the control lies with the selected few.

Disadvantages of Permissioned Blockchains

The most prominent drawback of a permissioned blockchain is that it is not truly decentralized as one would imagine a typical blockchain. The control in the hands of very few validators makes it less democratic. Secondly, lack of sufficient validators makes the network a bit insecure. And, if validators agree, the information in the blocks can be altered.

Advantages of Permissionless Blockchains

1. True Decentralization

If you have resources and meet certain criteria, you can become a validator in a permissionless blockchain. The control is not limited to a selected minority. Participation in the consensus mechanism is open to all who are eligible.

2. Ease of Access

Anyone can create a wallet and join a permissionless network as these networks are easily accessible and have relatively low barriers to entry.

3. Resilience

A permissioned blockchain may die if validators leave the network. If the authorities choose, it may be banned. However, a permissionless blockchain is borderless and resilient. Even if a few validators leave, others join. If a government chooses to ban it, the blockchain continues working in other regions.

4. Strong Consensus Mechanism

A large number of validators makes permissionless blockchains very strong. These networks are immutable in real sense of the word.

Demerits of Permissionless Blockchains

Maintenance costs of permissionless networks are enormous. They need strong consensus mechanisms to keep bad actors out. Proof-of-Work, for example, demands massive computational power. Proof-of-Stake requires substantial financial staking. These mechanisms are essential for security, but they also make the network slower and sometimes expensive. When millions of people try to use the same chain, congestion becomes a real issue. Transparency may sometimes prove a security threat when sensitive information leaks. Finally, fee spikes and delayed transactions are common on popular public networks.

Which Option is for You?

Whether you want to become a developer or a participant in a blockchain network, the matter of selection depends on various factors. If you prefer the philosophy of decentralization and true decentralization, permissionless blockchain is better. If you want a blockchain for an organization or institution, permissioned networks are the option for you.

Conclusion

In brief, both kinds of blockchain have their strengths and weaknesses. For a larger setup, an open and permissionless blockchain suits better. Contrarily, permissioned networks can be chosen for a closed environment.