The Sybil attack happens in the peer-to-peer network. A malicious attacker wishes to carry out this attack on the bitcoin network. In this, a node in the network operates multiple identities at the same time and undermines the authority in the reputation system. Its main aim is to gain the majority of influence in the network to carry out illegal actions in the system.
The Sybil attack is difficult to detect and prevent, but the following measures can be useful:
- By increasing the cost of creating a new identity.
- Require validation of identities or trust for joining the network.
- Give different power to different members.