Multi-Chain Restaking with Trustless Bridging

Exocore seamlessly interfaces with both L1 and L2 blockchains through a trustless bridging mechanism without in- troducing an additional trust assumption. In the Exocore “exosystem,” these blockchains are called “client chains.” To monitor state changes on these client chains, Exocore validators collectively operate light clients to securely verify the state changes. Exocore uses the ZK (Zero-Knowledge) light client developed by Polyhedra [10] and hosted on Lay- erZero [19] for the chains already supported. This brings the most secure and trustless mechanism for Exocore to verify state change on client chains. For other chains not supported by ZK light client, the traditional Simplied Payment Verifi- cation (SPV) style light client will be used as an alternative. For performing control actions on the client chains, Exocore validators collectively initiate a Threshold Signature Scheme (TSS) protocol [7], facilitating the signing of a client chain transaction. It’s important to note that malicious transactions signed by TSS are not possible as long as the Exocore network itself is secure. Besides ZK and TSS as the basic cryptographic primitives, no other security assumption or third party can affect the security of Exocore’s bridging system.