VietMX Staff asked 3 years ago
Actually, it’s very easy to do damage to the network once you have 51%; just build your own chain faster than the network, and broadcast it whenever you like. If you send some of your coins to a new address in your own chain, all the transactions issued in the live network by spending those same coins will be reversed at the moment the longer chain is broadcast.
An attacker that controls more than 50% of the network’s computing power can, for the time that he is in control, exclude and modify the ordering of transactions. This allows him to:
- Reverse transactions that he sends while he’s in control
- Prevent some or all transactions from gaining any confirmations
- Prevent some or all other generators from getting any generations
The attacker can’t:
- Reverse other people’s transactions
- Prevent transactions from being sent at all (they’ll show as 0/unconfirmed)
- Change the number of coins generated per block
- Create coins out of thin air
- Send coins that never belonged to him
