Sybil attacks or commonly called Sybil Attacks have often become a lively topic of conversation among the cryptocurrency community in recent months. Especially what happened in the retroactive airdrop distribution process for Arbitrum tokens, where a number of hackers took maximum advantage of this moment using the Sybil method.

So, what exactly is Sybil Attack? Why is it a major threat in the blockchain ecosystem? Read this article carefully so you can minimize the risk of hacker attacks.

What is a Sybil Attack?

Sybil Attack is a type of attack in which a person or group of hackers creates many fake identities called 'nodes' in order to control a peer-to-peer (P2P) network. Sybil's method is similar to someone cloning their social media account, and running multiple nodes (IP addresses or accounts) simultaneously on the network.

The term Sybil itself was first introduced by psychologist Flora Rheta Schreiber in 1973 when she described a woman with dissociative identity disorder (DID).

Sybil Attack In Blockchain and Airdrop

In the blockchain context, the term Sybil refers to someone who uses multiple accounts or a single crypto wallet to confuse and manipulate the network. Generally carried out by a group of hackers with sufficient resources to create large numbers of accounts and as much as possible make it appear that more people are involved in carrying out an on-chain activity than there actually are.

This method is commonly used to influence public opinion, make fraudulent transactions appear legitimate, and much more.

Lately, Sybil attacks have been infiltrated at Arbitrum airdrop token distribution events. Of course, this can easily happen, as creating a new identity in Web3 is as easy as generating a private key (in a simple test, one could generate around 120,000 keys/second using just one desktop device).

Sybil attacks increase at layer-2 due to lower transaction fees, so moving large amounts from wallet to wallet will only incur relatively small transaction fees to create the illusion of activity to get an airdrop.

In the case of Arbitrum, as many as 253 million ARB tokens were distributed among Sybil attackers. This was confirmed through a report made by Chinese Journalist, Colin Wu and the X-Explore team.

There are at least around 150,000 Sybil addresses and 4,000 Sybil communities that have successfully passed all airdrop eligibility checks. Simply put, almost one in four ARB tokens ends up in their pockets.

Are All Blockchains Vulnerable to Sybil Attacks?

In theory, each blockchain has its own vulnerabilities to Sybil attacks. However, to date no one has ever succeeded in carrying out a 51% attack or commonly known as a 51% attack on Bitcoin, because the large number of miners makes it more resistant to network takeover.

This means that the more miners validating transactions on a network, the better, as it would be very difficult for one entity to control as many as 51% of active miners.

Minval has discussed the explanation of Sybil Attack as a form of basic knowledge of the many threat risks of attacks in the blockchain, but it doesn't stop here, Minval will also create a more in-depth article about Sybil so that at least Valunian can minimize attacks on managed accounts.