Miners Exploit Recent Bug to Launch 51% Attack on the Bitcoin Cash Network

Bitcoin Cash (BCH) Losses 7.26% After Hard Fork

Bitcoin Cash recently upgraded its network to integrate the Schnorr Multisig feature. As good as the development was with the advantages of Schnorr, it led to a fault that would have cost Bitcoin Cash more than the advantages of Schnorr. Two miners, BTC.TOP and BTC.COM took advantage of an unintentional split to launch a 51% attack on the network during the upgrade.

Checksum0, an independent miner says BTC.TOP and other pools were intentionally mining empty blocks to lengthen the blockchain from a split on the Bitcoin Cash blockchain. Invalid transactions were sent to ABC node’s mempool but miners, however, were able to quickly detect and diagnose the issue and reported to ABC, checksum0 explained.

ABC quickly took care of the problem with a fix in no time so that things returned to normal. Although there have been rumors that the attack was as a result of the upgrade, checksum0 thinks otherwise.

“This is totally unrelated to today’s upgrade, or any upgrade for that matter.  This is a bug that was specific to ABC code,” he insisted.

Chief Scientist at Bitcoin Unlimited, Peter Rizun also said the bug was just exploited at the time of the upgrade to create the impression that it was related to the upgrade.


“It was a vulnerability that someone sat on for a long time and chose today to exploit, to make the bug appear more related to the network upgrade than it was. It was really more of a nuisance than anything: it just caused ABC miners to mine empty blocks until they got patched.”

A professor at Cornell University, Emin Gün Sirer added that it was a small bug that was exploited, a common problem with decentralized networks but nothing more. It is unclear why the attackers chose to strike during the upgrade, but it would appear they wanted to invalidate the reliability of the upgrade by disrupting the normal functioning of mining activities.

A Twitter user Guy Swann seems to be seriously disturbed by the incidence and how no one seems to have noticed or said anything about the attack. He, however, points out that this has significant implications on the integrity of Bitcoin Cash network.

“There are at least a few people (maybe only partially) realizing that this basically kills any perception that #BCH is “decentralized, censorship resistant money,” he said.