How Does a Delayed Block Finality Mechanism Help Defend against Double-Spends?

A delayed block finality mechanism requires a much higher number of confirmations (e.g. 100 or more) before a transaction is considered irreversible or "final." For an attacker to successfully double-spend, they must secretly mine a longer chain that overcomes this high confirmation threshold.

This significantly increases the cost and time required for the attack, making it economically unviable for most small-scale attackers. It forces exchanges to wait longer before crediting deposits.