What is the difference between a public and a private blockchain?
Published Sep 18, 2026Updated Sep 19, 2026Last verified Sep 18, 2026Requests recorded in this site’s own server logs, with the crawler identity checked by reverse DNS or IP range.Google4First collected Sep 19, 2026Recent requestsGoogleSep 20, 2026GoogleSep 20, 2026GoogleSep 20, 2026GoogleSep 19, 2026
Quick answer
Anyone can join a public (permissionless) blockchain. NIST describes it as a system where all users' permissions are equal and not set by any administrator. A private or consortium (permissioned) blockchain requires every node and user to be granted permission, usually by an administrator or consortium. Public chains such as Bitcoin and Ethereum use proof of work or proof of stake. Permissioned chains such as Hyperledger Fabric can use lighter ordering protocols, because their participants are known.
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Answer
Sources
- governmentIR 8202, Blockchain Technology Overview — National Institute of Standards and Technology (NIST) · accessed Sep 19, 2026 · Evidence page
- governmentGlossary: permissioned — NIST Computer Security Resource Center · accessed Sep 19, 2026 · Evidence page
- governmentGlossary: permissionless — NIST Computer Security Resource Center · accessed Sep 19, 2026 · Evidence page
- governmentGlossary: smart contract — NIST Computer Security Resource Center · accessed Sep 19, 2026 · Evidence page
- officialBlock Chain — Bitcoin Developer Guide — Bitcoin Project (developer.bitcoin.org) · accessed Sep 19, 2026 · Evidence page
- governmentThe story of Satoshi Nakamoto and the 1 million bitcoins — European Commission, CEF Newsroom · accessed Sep 19, 2026 · Evidence page
- otherStuart Haber — Wikipedia · accessed Sep 19, 2026 · Evidence page
- officialThe Merge — ethereum.org · accessed Sep 19, 2026 · Evidence page
- officialProof-of-stake (PoS) — ethereum.org · accessed Sep 19, 2026 · Evidence page
- officialBlocks — ethereum.org · accessed Sep 19, 2026 · Evidence page
- officialIntroduction — What is Hyperledger Fabric? — Hyperledger Foundation (Linux Foundation) · accessed Sep 19, 2026 · Evidence page
- academicBitcoin electricity consumption: an improved assessment — Cambridge Judge Business School, University of Cambridge · accessed Sep 19, 2026 · Evidence page