Bitcoin Researcher Explains Why Block Reorg Was Not Malicious Attack

Following a rare two-block reorganization on the Bitcoin network that saw Foundry USA orchestrate a massive seven-block winning streak, fears of foul play began circulating within the community.

However, a Bitcoin researcher has stepped in to debunk the rumors.

The anomaly was simply expected network behavior rather than a coordinated “selfish-mining” attack.

The race at height 941880

As reported by U.Today, the network briefly split into two competing chains at block height 941880.

AntPool mined block 941881, and this was followed up with block 941882 on that same path by ViaBTC.

Simultaneously, Foundry USA mined its own versions of blocks 941881 and 941882.

The network briefly had two valid chains of equal length until Foundry USA broke the tie by continuing its streak, mining blocks 941883, 941884, and 941885.

This resulted in the AntPool and ViaBTC blocks being orphaned. The Foundry ended up being the victor of an epic seven-block run.

The selfish mining theory, debunked

Foundry seemingly materialized multiple blocks to overtake its competitors, and for some, the knee-jerk reaction was to accuse the pool of “selfish mining”.

A theoretical attack would involve a miner intentionally withholding valid blocks from the public network to gain a head start on finding the next block, ultimately wasting the hash power of competing pools.

According to the researcher, the data does not support this malicious narrative. If Foundry was attempting a selfish-mining attack, it was executed extremely poorly, given that the economic incentives were terrible.

It is worth noting that the event took place during a low-fee period. The two reorganized blocks only netted Foundry an infinitesimal 0.025 BTC in transaction fees.

Furthermore, on-chain data shows that Foundry actually spent a second mining on top of the AntPool and ViaBTC blocks before switching back to its own chain. A miner intentionally withholding a secret chain would not act this way.

The researcher attributes the event to standard network latency and the use of specific Bitcoin Core commands.