Privacy-Preserving and Incentive-Driven Relay-Based Framework for Cross-Domain Blockchain Interoperability
Saeed Moradi, Koosha Esmaeilzadeh Khorasani, Sara Rouhani
TL;DR
The paper tackles cross-domain interoperability between a permissioned blockchain (Hyperledger Fabric) and a permissionless blockchain (Substrate) by proposing a blockchain-agnostic, relay-based framework that embeds privacy-preserving routing and cryptographic techniques. It combines end-to-end encryption, blind and ring signatures, and source-obfuscation protocols (Dandelion++ and Clover) within a Cross-Chain Smart Contract ecosystem to securely forward transactions without exposing user identities. The authors provide a formal security analysis under STRIDE with collusion considerations and evaluate performance metrics such as forwarding time, throughput, availability, and anonymity under varying network conditions, finding Clover generally offers a better privacy-utility trade-off in partially compromised networks. The practical significance lies in enabling enterprise-grade cross-chain interoperability with robust privacy guarantees, while highlighting the trade-offs between anonymity and efficiency for real-world deployments.
Abstract
Interoperability is essential for transforming blockchains from isolated networks into collaborative ecosystems, unlocking their full potential. While significant progress has been made in public blockchain interoperability, bridging permissioned and permissionless blockchains poses unique challenges due to differences in access control, architectures, and security requirements. This paper introduces a blockchain-agnostic framework to enable interoperability between permissioned and permissionless networks. Leveraging cryptographic techniques, the framework ensures secure data exchanges. Its lightweight architectural design simplifies implementation and maintenance, while the integration of Clover and Dandelion++ protocols enhances transaction anonymity. Performance evaluations demonstrate the framework's effectiveness in achieving secure and efficient interoperability by measuring the forwarding time, the throughput, the availability, and their collusion impact of the system across heterogeneous blockchain ecosystems.