: Automated payment processors or exchanges with low confirmation thresholds.
: Most modern exchanges and Bitcoin services mitigate this by requiring three to six confirmations before funds are cleared, making the cost of maintaining the fake chain prohibitively expensive for an attacker. Key Characteristics Bitcoin_Fake_Transaction_Vector76_attack_Full_V...
: Once the exchange credits the account based on that one confirmation, the attacker withdraws the funds. Meanwhile, the rest of the network follows a different chain (where the original block was orphaned), and the transaction to the exchange is ultimately rejected as a double spend. Technical Context & Mitigation : Automated payment processors or exchanges with low
: The merchant/exchange loses the goods or currency, while the attacker retains their original Bitcoin on the main chain. Meanwhile, the rest of the network follows a
The attack combines elements of a and a Race attack by leveraging a pre-mined block.
: The exchange sees the transaction to Address C and then sees the attacker's block arrive. Because the block is valid, the exchange's node may count the transaction to Address C as having one confirmation , even though that transaction is not actually in the block.
: Once the attacker finds a block, they quickly send a second transaction—sending the same coins from Address A to the exchange's Address C—directly to the exchange's node.
