Relayer Network Centralization
Relayer network centralization refers to the reliance on a small or controlled group of entities to monitor events on a source chain and relay them to a destination chain within a cross-chain bridge. If these relayers are centralized, they become a single point of failure and a target for censorship or malicious activity.
A centralized relayer set could collude to steal locked collateral, censor specific transactions, or provide false information to the destination chain. This undermines the decentralized nature of the bridge and introduces trust assumptions that contradict the ethos of permissionless blockchain systems.
To mitigate this, developers move toward decentralized relayer networks that use economic incentives, staking, and random selection to ensure honesty and availability. Centralization risk is a primary concern for users evaluating the security of bridges, as it directly affects the immutability and censorship resistance of the bridged assets.