Orphan Block
Written by Alex Gedevani
Introduction
Orphan blocks also called detached blocks, are valid and verified blocks, which have not been accepted into the blockchain network due to time delays concerning acceptance of the block compared to the other qualifying block. The difference between an orphan block and the winning block often comes down to a few seconds.
During the mining process, miners attempt to generate new blocks. The miner who successfully finds a new block is entitled to the block reward. There is a possibility that two miners produce blocks at a similar time. This scenario occurs since the acceptance of blocks into the blockchain is not simultaneous, given delays in block validation by Proof of Work (PoW) miners. When deciding between 2 blocks, the block with the larger share of hash power gets accepted into the main chain. The other block with the smaller PoW is not accepted and becomes an orphan block, ending up on the shorter chain.
Orphan blocks can also be created when an attacker with sufficient hashing power, attempts to reverse transactions. Mitigating this risk, transactions are only considered complete after the blockchain is six blocks ahead of the block containing the transaction.
Orphan blocks are commonly linked to the Bitcoin network. The Bitcoin Block Explorer provides more information about orphaned blocks which are available online.
Suggested Reading
What are Uncle Block, Orphaned Block and Stale Block in Blockchain by Coinguides
What is an Orphan Block? by Jerome Morrow
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