A public ledger that is open to anyone, without being controlled by a single owner.
An unpermissioned ledger — also known as permissionless or public — is a ledger that anyone can access and download. Users can submit messages for processes and even be involved in processes of authentication, verification, and consensus protocol for blockchain transactions.
Unlike permissioned ledgers, all users of unpermissioned ledgers can create data, publish smart contracts and run a node. As such, unpermissioned ledgers are completely transparent as data are accessible to anyone. They also incentivize users to run nodes.
There are, however, a few drawbacks. For example, performance is slow and energy consumption is extremely high. Bitcoin and Ethereum are two examples of unpermissioned ledgers.
