How Does Increasing the Confirmation Count Mitigate a Double-Spending Attack?

A double-spending attack requires the attacker to reverse a transaction by mining a longer, private chain. When an exchange increases the required confirmations, it means they wait for many blocks to be added after the deposit block.

Each new block makes the deposit transaction deeper in the chain. Reversing a transaction buried under many blocks becomes exponentially more difficult and expensive for the attacker, as they must re-mine all subsequent blocks.

This significantly increases the economic barrier for the attack.