Building Interoperability: A Decentralized Bridge Connecting Polkadot and Cosmos Ecosystems

Cross-chain interoperability remains a critical challenge in blockchain technology, especially as the number of decentralized networks continues to rise. Each blockchain operates in isolation, creating an urgent need for solutions that enable seamless interactions across these networks. This paper presents a Proof-of-Concept (PoC) solution for bridging interoperability between the Polkadot and Cosmos multi-chain ecosystems. Currently, no existing solution facilitates secure cross-chain interactions between these platforms. Our approach addresses this gap by utilizing a hashed timelock mechanism, introducing a modular and reusable framework that can be deployed in fully operational networks. Built on smart contracts and the Substrate framework, the proposed solution relies on relayers - trusted, incentivized, and fairly selected API servers -to manage communication and proof exchange between chains. This framework serves as a foundational step toward developing robust cross-chain solutions for integrating Polkadot, Cosmos, and similar networks.