What are Double Spend Proofs (DSPs)?

Double-Spend Proofs (DSPs) are a crucial defense mechanism within the Bitcoin Cash network, designed to protect against attempts to send funds to a merchant and simultaneously send the same funds back to the sender — a fraudulent act known as double spending. The fundamental idea is to prevent a user from evading payment while the merchant remains under the impression that the transaction has been settled.

In the context of cryptocurrency transactions, the risk of double spending occurs between the creation of a transaction and its inclusion in a block. The absence of a clear indicator of risk during this period poses a challenge, especially for merchants who lack real-time information about the transaction's legitimacy. DSPs serve as a digital warning system, providing an early signal of potential malicious activity.

The primary achievement is the creation of a cryptographic message - actual proof that a double-spend has been attempted - that serves as an alert for potential harm to the network. This message allows the Bitcoin Cash network to identify and defend against various attacks, promising a shortened settlement time and reducing overall risk.

Learn more about Double-Spend Proofs and other Bitcoin Cash technical features in our broad exploration of Bitcoin Cash upgrades.