Trust between entities in any scenario without a trusted third party is very difficult, and trust is exactly what blockchain aims to bring into the digital world with its basic features. Many applications are moving to blockchain adoption, enabling users to work in a trustworthy manner. The early generations of blockchain have a problem; they cannot share information with other blockchains. As more and more entities move their applications to the blockchain, they generate large volumes of data, and as applications have become more complex, sharing information between different blockchains has become a necessity. This has led to the research and development of interoperable solutions allowing blockchains to connect together. This paper discusses a few blockchain platforms that provide interoperable solutions, emphasising their ability to connect heterogeneous blockchains. It also discusses a case study scenario to illustrate the importance and benefits of using interoperable solutions. We also present a few topics that need to be solved in the realm of interoperability.

翻译：在任何缺乏可信第三方的场景中，实体间的信任都极难建立，而区块链正是旨在通过其基本特性将信任引入数字世界。随着越来越多的应用转向区块链，用户得以在可信环境中进行操作。早期区块链存在一个缺陷：它们无法与其他区块链共享信息。随着更多实体将其应用迁移至区块链，产生了海量数据，且应用日趋复杂，跨区块链的信息共享已成为必然需求。这推动了允许区块链相互连接的互操作性解决方案的研发。本文探讨了若干提供互操作性解决方案的区块链平台，重点关注其连接异构区块链的能力，并通过案例研究阐明采用互操作性方案的重要性与优势。同时，我们提出了互操作性领域亟待解决的若干议题。