What Is Finality And Re-Organization (Re-Org) In A Blockchain?
Finality is the moment a transaction is considered permanent and irreversible on the blockchain. Its absence leads to a Re-Organization (Re-Org), a network event where a previously accepted block or chain segment is discarded in favor of a new, longer, and more valid chain, temporarily reversing transactions in the discarded blocks.
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🕒 7:30 PM
📅 Oct 29, 2025
✍️ By Nathanael707
Defining Transaction FinalityFinality is the guarantee that a transaction will never be reverted. Different consensus systems offer different types of finality:
Probabilistic Finality (PoW): Certainty increases with each new block mined on top; never 100% final, but economically irreversible after 6-10 confirmations.
Economic Finality (PoS): Near-instant, strong finality secured by the threat of massive economic penalties (slashing) for validators who attempt to revert history.
Defining a Block Re-Organization
A Re-Org is a fork resolution event where the network adopts a chain that is longer than the one currently being followed.
Cause: Usually due to network latency, where two validators find valid blocks at the same time, or an attempt to execute a double-spend attack.
Impact: Transactions included only in the orphaned (discarded) blocks are temporarily reversed and put back into the transaction pool.