Bridges Between Islands - Cross-Chain Technology for Distributed Ledger Technology.

Since blockchain’s emergence in 2008, we see a kaleidoscopic variety of applications built on distributed ledger technology (DLT) today, including applications for financial services, healthcare, or the Internet of Things. Each application comes with specific requirements for DLT characteristics (e.g., high throughput, scalability). However, trade-offs between DLT characteristics restrict the development of a DLT design (e.g., Ethereum, blockchain) that fits all use cases’ requirements. Separated DLT designs emerged, each specialized to suite dedicated application requirements. To enable the development of more powerful applications on DLT, such DLT islands must be bridged. However, knowledge of cross-chain technology (CCT) is scattered across scientific and practical sources. Therefore, we examine this diverse body of knowledge and provide comprehensive insights into CCT by synthesizing its underlying characteristics, evolving patterns, and use cases. Our findings resolve contradictions in the literature and provide avenues for future research in an emerging scientific field.