Sybil attacks undermine an online network by creating many IDs, accounts or nodes to upset the balance of power.
Sybil attacks can be simple in nature, like setting up duplicate accounts on social media, or they can be complex, like operating multiple nodes on a blockchain system. Both of these tactics are designed to gain influence or power over a network. The name “Sybil” originates from a medical case study of a woman that had dissociative identity disorder.
In blockchain systems, a bad actor may attempt to disrupt a network’s power structure by gaining as many node IDs as possible. Sybil attacks attempt to centralize power in these decentralized networks: blockchain technology can be uniquely manipulated by this since processes are commonly automated, and DAOs are usually small teams of engineers and developers.
On peer-to-peer networks creating a multitude of identities could quickly consolidate power over the network. This is unlike an eclipse attack where a hacker will compromise just one by manipulating its actions. Sybil attacks instead use many nodes to manipulate information sent or received on the network. This can be incredibly effective when considering the unique inter-reliance and connectivity that decentralized systems have.