What Is a 51% Attack and What Is Its Potential Impact on a Cryptocurrency Network?

A 51% attack occurs when a single entity or group gains control of more than half (51%) of the network's total mining hash rate. With this majority power, the attacker can effectively control the ordering of transactions and prevent new transactions from gaining confirmation.

Critically, they can perform "double-spending," where they reverse their own transactions, severely undermining the integrity and trust in the blockchain.

What Is the “51% Attack” and How Does It Relate to a Pool’s Size?
How Does Double-Spending Fundamentally Undermine a Cryptocurrency’s Value Proposition?
What Countermeasures Can a Blockchain Implement to Recover from a Successful 51% Attack?
What Is ‘Double-Spending’?
What Is ‘Double-Spending’ and Why Is It a Concern?
What Is ‘Double-Spending’ and Why Is It the Main Concern of a 51% Attack?
What Is the Difference between a 51 Percent Attack and a Double-Spending Attempt?
What Is the Risk of a Single Mining Pool Accumulating a 51% Hash Rate?

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