What is the key difference between public and private blockchains?

The key distinction between public and private blockchains lies in their access control and governance structures. Public blockchains are designed to be open and inclusive, allowing anyone to participate in the network, validate transactions, and contribute to the ledger. This open-access model fosters a decentralized environment where transparency and participation are paramount.

In contrast, private blockchains are restricted to specific users, typically managed by a central authority or a consortium of entities. This means that access to the network is controlled, and only authorized participants can engage in transaction validation and data sharing. Such a design is often employed in enterprise settings where confidentiality, regulatory compliance, and control over the data are crucial.

While security can vary based on implementation in both types of blockchains, the controlled nature of private blockchains generally provides a different security mechanism that is aligned with business requirements, rather than the open trust model of public blockchains.

This understanding of access and governance is essential for choosing the right type of blockchain for a given application or business scenario. Thus, it highlights the fundamental difference in how these two types of blockchains operate.