What Is a ‘Race Attack’ and How Does It Differ from a 51% Double-Spend?

A race attack is a simpler, less powerful form of double-spending where the attacker sends two conflicting transactions almost simultaneously to different nodes or the merchant and the network. The goal is to have the merchant accept the first transaction (the deposit) before the network accepts the second transaction (the reversal) into a block.

It relies on timing and network latency and does not require 51% hash power, unlike the more sophisticated 51% attack.