Abstract
Blockchain networks rely on different forms of governance, consensus, data and execution, which makes it difficult to achieve secure cross-chain data exchange. Existing interoperability approaches often rely on intermediaries, protocolspecific mechanisms, or limited validation, leaving gaps in trust minimization, data integrity and protection against cross-chain attacks. This paper proposes PolyConnect, a security-centric interoperability framework for verifiable and trust-minimized data exchange across heterogeneous blockchain networks. PolyConnect uses a standardized JSONbased record representation and combines hash validation, digital signatures, zero-knowledge proofs and blockchainstate/replay validation to provide layered cross-chain verification. The framework was evaluated across private, consortium, public and hybrid blockchain configurations using workloads of 100, 500 and 1000 records, with ten independent trials for each configuration. Evaluation considered processing performance, heterogeneous data format processing, attack detection, security coverage and comparison with representative interoperability approaches. Across 14 predefined attack scenarios, the complete validation pipeline detected 12 scenarios, achieving an Attack Detection of 85.71%, while the Security Coverage Metric reached 87.5% across eight security categories. Data Fetch and Serialization Time remained below 1 second across the evaluated heterogeneous data categories. Performance analysis showed that processing time varied substantially with workload size and blockchain configuration. Comparative analysis further showed that PolyConnect reduces intermediary dependence and provides broader security coverage but introduces higher computational and deployment overhead. These findings position PolyConnect as a security-focused approach that prioritizes verifiability, auditability and trust minimization in heterogeneous blockchain interoperability.
Keywords: Auditability, Interoperability, Cross-chain Communication, Data Integrity.