A public blockchain is a non-restrictive, permission-less distributed ledger system. Anyone who has access to the internet can sign in on a blockchain platform to become an authorized node and be a part of the blockchain network. A node or user which is a part of the public blockchain is authorized to access current and past records, verify transactions or do proof-of-work for an incoming block, and do mining. The most basic use of public blockchains is for mining and exchanging cryptocurrencies. Thus, the most common public blockchains.

Advantages of Public Blockchain

1.Trustable – Unlike in private blockchain, two nodes or participants do not need to worry about the authenticity of the other. In other words, they don’t need to personally know or trust the other nodes as the process of proof-of-work makes sure there can be no fraud in transactions. So, one can trust public blockchains blindly without feeling the needing to trust individual nodes.

2.Secure – There can be as many participants or nodes in a public network which makes it a secure network. The larger the network, greater the distribution of records and harder it is for hackers to hack the entire network. In addition to this, every node will do verification of transactions and proof-of-work which makes every transaction and block legitimate. Due to these practices and thoughtful cryptogenic encrypting methods, a public blockchain is much safer than the private one.

3.Open and Transparent – Public blockchain is open and the data is transparent to all the participant nodes. A copy of the blockchain records or digital ledger is available at every authorized node. This makes the entire blockchain system completely open and transparent. No one shows a fake transaction or hides an existing one as every node has an updated copy of the database at any given point of time.

Disadvantages of Public Blockchain

1.Lower TPS – The rate of transactions per second in a public blockchain is very low. This is because it is a huge network with a lot of nodes and for every node to verify a transaction and do proof-of-work is time-consuming. This is why public blockchains like Bitcoin can process only 7 transactions per second or Ethereum network has a rate of 15 TPS. On the other hand, a private network such as Visa has a rate of 24,000 TPS indicating a huge difference in speed of transaction processing and execution.

2.Scalability Issues – Like we just saw in the point above, that public blockchain have a slow rate of processing and completing transactions. This causes issues in scalability as well. Because the more we try to increase the size of the network, the slower it will get. However, solutions like Bitcoin’s Lightning Network helps in overcoming this problem. It maintains a rate of the transaction as we increase the size of the network.

3.High Energy Consumption – The process of proof-of-work is highly energy consuming as it needs specialized systems (hardware components) to run a special algorithm. It is a matter of concern from both an environmental and economical standpoint. The apparatus to do proof-of-work is costly and consumes as much energy as the country of Ireland! The technology definitely needs to come up with energy-efficient consensus mechanisms.