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
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
are two examples of unpermissioned ledgers.