AntPool Mining Pool Attempts to Mine Rogue Bitcoin Block

Neil Dennis

A rogue block on the Bitcoin blockchain was identified on Thursday morning, but it remains unclear whether it was a fault in the software, or a more malicious motive.

At block height 584,802, bitcoin miner AntPool attempted to publish an invalid block on the network. The error was identified by all eight validation nodes at forkmonitor.info.

Transaction Fees but No Transactions

The erroneous block was submitted at 14.35:27 UTC, 21 seconds after the previous block and contained no transactions, although the coinbase value of the block suggested it included transaction fees. 

BitMEX Research noted that the invalid block submission coincided with a drop in the price of bitcoin, but admitted it was probably just a coincidence.

AntPool eventually mined the valid block number 584,802, suggesting an error in the software had been responsible for its invalid submission. However, adding to the confusion of the episode, the valid block number 584,802 contained a total of 2,455 transactions, but fees of just 0.64968988 - only about 50% of the attempted charge of the invalid block.

Bug to Blame?

An expensive mistake, then. Jameson Lopp, a blockchain developer, suggested a "bug in the block template generator" was responsible.

This leaves the question hanging: could we be seeing more episodes of this kind? AntPool declined to comment or make a statement about the incident.