Security Challenges in Building Blockchains Bridges and Countermeasures

: The implementation of distributed ledger technologies and Blockchains has recently become high in various domains, from finance to governance. There are multiple Blockchain frameworks and networks for different use cases but still seems to be a gap in how different frameworks, protocols, and ledgers interact with each other. With the increase in the adoption of Blockchains, there is an increasing need for suitable interoperable solutions so that more value can be provided to the end user. This research focuses on analyzing how current Blockchain bridges are built and evaluating common security risks and countermeasures within the scope of interoperability. A threat model is proposed to analyze blockchain interoperability's various components, vulnerabilities, risks, and corresponding mitigation techniques. Common security vulnerabilities like centralization of trust and vulnerable smart contracts and others were identified and classified based on the kind of bridge component along with possible mitigations. Each solution, like Relays, HTLCs, Notary Schemes, and Smart Contracts, is explored. Thus, the study will help developers understand the risks involved by providing insights and pointing out the need for standardization on Blockchain interoperable solutions.