Sybil accounts in cryptocurrency and blockchain systems are fake or duplicate accounts created by a single person or group to manipulate the system. The main goal of Sybil attacks is to give the appearance of many participants in the network, thereby influencing its operation, bypassing restrictions, or gaining advantages in decentralized systems.

Uses of Sybil Accounts in Cryptocurrencies and Blockchains

Sybil accounts can be used for various purposes in cryptocurrency and blockchain systems:

• Voting: In some blockchains, decisions are made through participant voting. Sybil accounts can artificially increase the number of votes for a particular decision.

• Network Attacks: Sybil attacks can be used to gain control over the network, especially in decentralized networks where actions are determined by the majority (such as in Proof-of-Stake consensus networks).

• Reputation Attacks: In blockchains with reputation systems, Sybil accounts can create artificially high or low reputation for certain addresses, affecting the trust in them within the network.

• Rewards and Airdrops: In some projects, rewards are given to a single account. Sybil accounts can be created to collect multiple such rewards.

Methods of Protecting Against Sybil Accounts

Blockchain systems use various methods to protect against Sybil accounts, including:

• Verification methods
• Registration limits
• Consensus algorithms like Proof-of-Work and Proof-of-Stake