Before and after almost every major airdrop, one term tends to come up: Sybil. Projects try to identify Sybil accounts, airdrop farmers try to avoid detection, and ordinary users may get caught in the crossfire. Understanding the issue can help you avoid a lot of pitfalls.

$ZRO is LayerZero’s token. Before its 2024 airdrop, the project specifically investigated addresses with multiple accounts. Current price: 1.705 (24h +1.67%).

■ What Is a Sybil Attack?

A Sybil attack is a concept in cybersecurity. It refers to one person controlling many fake identities and posing as multiple independent users. In airdrops, “Sybil” usually refers to addresses that use batches of wallets to repeatedly farm eligibility.

The original purpose of an airdrop is to distribute tokens and governance rights to real users. If a large share goes to a small number of people farming with multiple accounts, the distribution loses its meaning, so projects put a great deal of effort into screening for this.

■ How projects investigate

A common method is correlation analysis: checking whether funds for different addresses came from the same source, whether their interactions happened at highly similar times, and whether they followed exactly the same transaction paths. The more alike the patterns, the more likely the addresses are controlled by the same person.

Before distributing ARB in 2023, Arbitrum screened for Sybil activity. Before its 2024 airdrop, LayerZero published a preliminary list of around 800,000 addresses suspected of being Sybil accounts. Addresses identified as Sybil accounts were not eligible for the full airdrop.

■ A distinctive approach

In May 2024, LayerZero let users with multiple accounts voluntarily disclose them: addresses that self-reported could keep 15% of their original allocation, while the rest was redistributed to eligible users. It then opened a reporting program, with successful reporters receiving a share of the rewards.

This approach shows that projects are taking an increasingly strict stance against Sybil activity, and that the costs and risks of farming are also rising.

■ A reminder for everyday users

Sybil detection relies on statistical patterns, so legitimate users may inevitably be caught by mistake. If you believe you were wrongly flagged, check whether the project has an appeals process.

Stay away from tools and services claiming to “farm airdrops for you” or “guarantee eligibility.” Many will ask you to import your private key or seed phrase. Don’t trust unfamiliar “eligibility checker” websites either; rely on official project announcements for airdrop eligibility.

■ Summary

Airdrops are never an obligation for projects, and the rules are continually getting stricter. Rather than spending a lot of time and money farming accounts, it’s better to spend that time understanding the project itself. Don’t place trades just because everyone around you is doing it.

Anything I missed? Let’s talk in the comments.