Marathon mined a block which was not compliant with the consensus rules by an error due to ‘experiments’. The network correctly rejected the block
The Incident Unveiled
On September 27, 2023, Marathon Digital, a leading Bitcoin mining company, found itself in an unusual situation. The company confirmed that it had mined an invalid Bitcoin block at height 809478. This was not a deliberate act but the result of a bug that occurred during an experiment.
Marathon Digital stated, “We utilize a small portion of our hash rate to experiment with our development pool and research potential methods to optimize our operations. The error was the result of an unanticipated bug that came from one of our experiments.“
The invalid block contained a transaction that was ordered incorrectly with a spending output transaction, leading to its rejection by other node operators.
The news was first brought to light by an anonymous Bitcoin developer known as “0xB10C,” who pointed out that Marathon’s mining pool, MaraPool, had a “transaction ordering issue.” This was later confirmed by CasaHODL co-founder Jameson Lopp and further analyzed by BitMEX Research.
Implications for Bitcoin’s Network Security
The successful mining of an invalid block would not have been a minor setback; it would have had wider implications for the Bitcoin network. However, the rejection of the invalid block by other nodes in the network was cited by Marathon as evidence of Bitcoin’s robust security mechanisms. The company stated, “In no way was this experiment an attempt to alter Bitcoin Core in any way. The incident underscores the robust security of the Bitcoin network, which rejected and rectified the anomaly.”
This incident serves as a testament to the decentralized and self-correcting nature of the Bitcoin network. In traditional centralized systems, such an error could lead to significant vulnerabilities, requiring manual intervention.