The distributed ledger technology (DLT) landscape comprises a wide range of independent networks with little to none built-in interoperability. To be applied in traditional enterprises, these DLT systems must also interact with legacy systems with no support for the processes of a DLT. An important topic in DLT research is, therefore, to establish standardised protocols for cross-network transfer and exchange of data and assets. Ideally, these protocols should be general-purpose so that they can be applied on top of many different types of ledger systems. One such protocol, supporting asset transfer, is the Secure Asset Transfer Protocol (SATP) in development by the Internet Engineering Task Force (IETF). The SATP Core protocol draft by Hargreaves et al. (2025) describes an interoperability protocol that can facilitate asset transfer between two DLT systems, as well as between a DLT system and a non-DLT system. In either case, SATP imposes no restrictions on the underlying system implementations. Building on this work, in this paper, we present an adaptation of SATP that facilitates cross-network asset exchanges. This asset exchange protocol, named the Secure Asset Exchange Protocol, inherits the key advantages of SATP but enables asset exchanges instead of asset transfers.

Securely transferring tokenised assets between largely non-interoperable blockchain networks is a great challenge to take on. Implementations must coordinate transactions on multiple blockchain networks which have inherently different characteristics and functionality. Moreover, implementations must coordinate transactions in strict order, in an atomic, synchronised way so that owners do not risk their assets becoming lost, while also mitigating the age-old problem of “avoiding double spend”. Several protocols for cross-network asset transfer, i.e. the bridging of assets, exist, and several production bridge implementations exist. However, frequent high-profile security breaches have arguably given bridges a bad reputation. Therefore, there is a clear need for standardised bridge protocols to re-establish trust. One initiative for standardising cross-network bridges is the Secure Asset Transfer Protocol (SATP) developed by the Internet Engineering Task Force (IETF). This protocol establishes four distinctive phases for the asset transfer process, driven by a standardised messaging cycle between specialised bridge orchestration applications, known as gateways. In this paper, we demonstrate a reference framework with functions needed to implement SATP. We describe our implementation of this reference framework, why SATP is unique and why SATP is likely to be an important contribution to powering future bridges.

Summary This paper presents a blockchain‐based architecture for our current electronic health record (EHR) systems. Being built on top of existing databases maintained by health providers, the architecture implements a blockchain solution to ensure the integrity of data records and improve interoperability of the systems through tracking all events that happen to the data in the databases. In this proposed architecture, we also introduce a new incentive mechanism for the creation of new blocks on the blockchain. The architecture is independent of any specific blockchain platforms and open to further extensions; hence, it potentially fits in with other electronic record systems that require protection against data misuse.