Let’s see few examples of Sybil Attack.

During the last US election, Russia was allegedly said to have interfered with the voting process. That’s a type of sybil attack as multiple fake accounts on Facebook were created and managed.

Another example can be seen with multiples reviews given to products on Amazon… and when you check carefully, it might be one person doing that with multiple accounts.

This attack falls in the category of pseudo-sybil attack because the platform used (Facebook) was not compromised itself.

A Sybil attack is a kind of security threat on an online system where one person tries to take over the network by creating multiple accounts, nodes or computers.

Binance Academy

The aim of this activity is to gain the most influence in the network to aid illegal actions in the system.

Types of Sybil Attack

In a direct attack, the honest nodes are influenced directly by the sybil node(s).

In an indirect attack, the honest node(s) are attacked by a node which communicates directly with the sybil node(s).

This middle node is compromised as it’s under malicious influence of sybil node(s).

What problems can Sybil attacks cause?

If enough pseudo identities are created, attackers can remove the honest nodes on the network so that they can control the entire network and do funny things like refusal to receive or transmit blocks, therefore, effectively blocking other users from a network.

If it gets too serious, a 51% Attack can also be launched.

Here, the attacker controls more than 50% of the network. At this point, double spending and other fraudulent acts can be done swiftly.

Scared?

Well, we’ll see how this can be managed or prevented in the Bitcoin network.

How does the Bitcoin network prevents sybil attack?

It uses the Proof of Work (PoW) consensus algorithm to prove the authenticity of any block that is added to the blockchain.

There’s an amount of computing power that’s required to locate blocks and add them to the network. With this energy consumption, no miner will want to waste it trying to do something nasty and then not been rewarded for it at last.

Other Ways to Prevent Sybil Attack

  • Allocate different levels of power or members.

Here, reputation is the key. The more reputable you are, the more power is given to you. So a newbie cannot come in and Reck the system.

  • Increase cost to create identity.

Why?

So that attackers will find it difficult to just create new, false identities.

  • Validation of identities before joining the network.

There are two kinds of validations: direct validation (where an already established member verifies the new member) and indirect validation (where an established member verifies some other members who can then verify new members).

This process makes it difficult to verify false accounts.

In general, everyone in the network needs to look out for each other as well as the network.

Indeed teamwork, plays a huge role here.