Chain Reversion Attack

A chain reversion attack, often associated with 51 percent attacks, occurs when an adversary gains enough control over a blockchain's consensus mechanism to rewrite history. By secretly mining a longer chain than the public one, the attacker can broadcast it to the network, forcing nodes to abandon the legitimate chain.

This allows the attacker to perform double-spending, where they spend assets on the public chain and then reverse the transaction using the private chain. In financial markets, this could be used to nullify large derivative settlements or withdraw collateral after an asset has been transferred.

It is a direct exploitation of the protocol physics governing decentralized ledger updates. Such attacks undermine trust in the entire ecosystem and can lead to massive liquidity drains.

Defensive measures include monitoring hashrate distribution and implementing circuit breakers for large transactions.