How Does Proof of Work Prevent the Double-Spending of Cryptocurrencies?

Proof of Work prevents double-spending by creating a chronological and immutable ledger of all transactions. When a new transaction is broadcast to the network, it is included in a block by a miner.

To be considered valid, this block must be accepted by the network and added to the blockchain. To reverse a transaction, an attacker would need to create a longer chain of blocks than the legitimate one, which would require immense computational power.

This makes it practically impossible to alter past transactions and spend the same cryptocurrency twice.

What Is ‘Double-Spending’ and Why Is It a Core Concern of a 51% Attack?
How Do Cryptocurrencies without Proof-of-Work (PoW) Consensus Address the Double-Spending Problem?
How Does the Immutability Provided by Merkle Trees Deter Double-Spending?
What Is the Role of Network Latency in Preventing Double-Spending?
How Can an Options Trader Use a “Synthetic Short” Position to Achieve a Similar Outcome to a Double-Spend?
What Is “Double-Spending” in the Context of a 51% Attack?
What Is a Transaction Confirmation and How Does It Relate to Double-Spending?
How Does a Double-Spend Attack Work Using 51% Control?

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