Marathon Allegedly Mined an Invalid Bitcoin Block

Marathon Digital Holdings (MARA), a publicly traded cryptocurrency mining company, reportedly mined an invalid block recently, according to developers, miners, and researchers.

The invalid block was identified at height 809478, with an anonymous Bitcoin developer stating that MaraPool, Marathon’s mining pool, experienced a “transaction ordering issue.”

Jameson Lopp, CTO of Casa, confirmed the finding, noting that data from all nine of his nodes indicated the block contained a transaction that incorrectly spent an output before it was created, rendering the block invalid.

Other Bitcoin node operators also rejected the invalid block.

BitMEX Research explained that the issue emerged because a transaction in the block was ordered incorrectly concerning a spending output transaction, violating consensus rules.

When a miner creates an invalid block, nodes that adhere to the Bitcoin protocol will reject it and not build upon it. Miners are motivated to create valid blocks according to consensus rules, as invalid blocks result in wasted resources and lost rewards.

Marathon Digital operates a significant mining operation with over 37,000 active miners and a hash rate of 3.2 EH/s. However, this incident highlights that even large mining pools are vulnerable to consensus rule violations that lead to wasted mining efforts.

The event serves as a minor reminder of the resilience of Bitcoin’s decentralized proof-of-work consensus mechanism. Major miners must still adhere to network rules and structure their blocks correctly; otherwise, their work will be rejected by the peer-to-peer network.