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Bitcoin Cash Users Survive 51% Attack

Summary

Bitcoin Cash (BCH) faced a 51% attack on May 15, 2019, in which a group of miners controlled the majority of the network’s hash power. Rather than an attempt at theft or network disruption, this was a unique situation where the miners intervened to prevent a malicious entity from exploiting a network upgrade to insert invalid transactions. The mining pools, BTC.com and BTC.top, spearheaded the move to protect the network’s integrity. Although no funds were stolen, the event highlighted the potential vulnerabilities in the network and raised questions about the extent of decentralization in Bitcoin Cash.

Attackers

The initial attack on the Bitcoin Cash network was attempted by an unidentified entity aiming to exploit a network upgrade by introducing invalid transactions. However, two major mining pools, BTC.com and BTC.top, counteracted by joining forces to temporarily control more than 51% of the network’s hash rate.

Losses

There were no financial losses incurred during the attack as the actions of BTC.com and BTC.top were directed by preventing the introduction of invalid transactions.

Timeline

  • May 15, 2019: An anonymous entity attempted to introduce invalid transactions into the Bitcoin Cash network during a scheduled upgrade.
  • May 15, 2019: BTC.com and BTC.top combined their hash power to launch a 51% counter-attack to reverse these invalid transactions.
  • May 15, 2019: The counter-attack was successful, and the invalid transactions were excluded from the blockchain. No funds were lost during the event.

Security Failure Causes

  • Network Centralization: The incident highlighted a centralization issue within the Bitcoin Cash network, as two mining pools were able to amass over half of the network’s hash rate. This centralization exposes the network to potential manipulation or unintended control.
  • Network Upgrade Vulnerability: The attack showed that scheduled network upgrades could be exploited by malicious actors aiming to introduce invalid transactions, revealing a need for enhanced security measures during these periods.