Unpermissioned Ledger
In short: An unpermissioned ledger is an open ledger that is not controlled by any single person and is accessible to everyone: anyone can read it, submit…
An unpermissioned ledger is an open ledger that is not controlled by any single person and is accessible to everyone: anyone can read it, submit transactions and, depending on the network, help validate them. Public blockchains such as Bitcoin and Ethereum work this way.
Why it matters
Open access means no single gatekeeper can block users or quietly rewrite the record, which is the basis of censorship resistance. Because participants do not know or trust each other, these networks rely on consensus mechanisms such as proof of work or proof of stake to agree on one version of the ledger. The trade-offs include fully public transaction data and lower capacity than systems run by a single operator. A permissioned ledger, by contrast, admits only participants approved by an operator or a group of members.
Example
Anyone with an internet connection can download Bitcoin's software, run a full node, check the entire transaction history and broadcast a payment, all without asking permission or opening an account. A company's private ledger works differently: new members must be approved, and the operator decides who may read or write records.