Security and Privacy Challenges in Blockchain Interoperability - A Multivocal Literature Review

Abstract

Transferring data and value across different blockchains is one of the biggest obstacles to further expansion. Blockchain interoperability allows different networks to communicate and transfer data between them and are increasingly crucial for blockchain applications. However, the concern about security and privacy in blockchain interoperability arises naturally. This work aims to provide the state-of-the-art related to security and privacy challenges in blockchain interoperability. We conducted a multivocal literature review (MLR) and analyzed 16 scientific and 30 grey literature, respectively. We examined different security and privacy challenges related to both blockchain in general and blockchain interoperability approaches such as Notary Schemes, Sidechains and Hashed Time-Lock Contracts. Possible mitigations are analysed, and open challenges that arose from the mitigations are highlighted.