Abstract

Proof-of-stake (POS) blockchains provide crypto-economic security for on-chain services, such as decentralized applications (DApps). However, off-chain services, including bridges, oracles, app chains, RPCs, sequencers, etc., are responsible for bootstrapping their own crypto-economic security. To solve this problem, EigenLayer introduced restaking, a new blockchain primitive that enhances the crypto-economic security of off-chain systems by utilizing staked ETH and other ETH-based liquid staking tokens. We propose Exocore, an omnichain restaking protocol that combines the crypto-economic security from multiple blockchain networks and tokens, and extends it to any off-chain system. The protocol is designed with a modular architecture, incorporating Tendermint-based Byzantine Fault Tolerant (BFT) consensus mechanism, Zero-Knowledge (ZK) light-client bridging, and a fully EVM-compatible execution environment. This design enables smooth interactions for restakers and seamless integration for developers. Additionally, we introduce novel concepts, such as Union Restaking, where off-chain services can form a union to extend the crypto-economic security of their own tokens to each other. By pooling crypto-economic security and extending it to off-chain systems, Exocore powers an open market for decentralized trust.