Security difficulties and barriers in building decentralized blockchain bridges, solution methods

Abstract

The use of distributed ledger technologies (DLTs) and blockchains is rapidly expanding across multiple sectors, including finance and governance. Although numerous blockchain frameworks and networks exist to support different use cases, a major challenge remains: enabling seamless communication between these diverse frameworks, protocols, and ledgers. As blockchain adoption accelerates, the need for effective interoperability solutions is becoming increasingly critical to deliver greater value to users. This study explores the design of current blockchain bridges and evaluates common security threats and mitigation strategies within the realm of interoperability. A threat model is introduced to examine the key components, vulnerabilities, risks, and corresponding safeguards involved in blockchain interoperability. Security concerns—such as excessive trust centralization and flaws in smart contracts—are identified and categorized based on the type of bridge component, along with recommended countermeasures. Different interoperability approaches—including relays, Hash Time-Locked Contracts (HTLCs), notary schemes, and smart contract-based solutions—are analyzed in detail. Ultimately, this research aims to help developers better understand the security challenges in blockchain interoperability and highlights the importance of establishing standardized practices in this area.