#bitcoin and other Altcoins using PoW and PoS mining mechanisms are no longer safe.
+ A 51% Attack is a potential threat to blockchain networks, occurring when an entity or a coordinated group controls more than 50% of the total computational power (hash rate) of the network in Proof-of-Work (PoW) systems like Bitcoin, or more than 50% of the total stake in Proof-of-Stake (PoS) systems.
When this majority control is achieved, the attacker can manipulate several aspects of the network, although they cannot change the fundamental rules of the protocol or steal money from other wallets.
+ What can an attacker do?
With control over 50%, the attacker can perform the following malicious actions:
Reverse their own transactions (Double Spending): This is the most common goal. The attacker can send money to a seller to receive goods/services, then use their majority power to remove that transaction from the public blockchain and refund the money to their wallet.
+ In addition to the 51% attack, quantum computing poses a significant potential danger.
