Abstract
The emergence of blockchain interoperability is reducing the risk of
investing in blockchain by avoiding vendor lock-in, leveraging
interoperation, and providing migration capabilities. However, to fully
unlock the internet of blockchains, it is necessary to provide
enterprise interoperability mechanisms that allow service providers to
comply with different regulations, e.g., data privacy regulations. Each
blockchain can be reached via a gateway, allowing to interconnect value,
to provide different services, and to enable self-sovereignty. To
realize this vision, we propose Hermes, a fault-tolerant middleware that
connects blockchain networks and is based on the Open Digital Asset
Protocol (ODAP). Hermes is crash fault-tolerant by allying a new
protocol, ODAP-2PC, with a log storage API that can leverage blockchain
to secure logs, providing them transparency, auditability, availability,
and non-repudiation. We introduce a use case benefiting from Hermes,
digital cross-jurisdiction promissory notes. We show that cross-chain
transactions can be achieved securely with Hermes, given that gateways
are complying with legal frameworks.