SWIFT's Phase 1 CBDC sandbox addressed the challenge of digital islands emerging from the proliferation of incompatible national CBDC systems. The initiative focused on proving that a single interoperability gateway could connect diverse domestic CBDC networks and existing payment rails, enabling seamless cross-border transactions without requiring system-level standardization.

The project needed to demonstrate that CBDC-to-CBDC flows between fundamentally different network architectures, specifically Ethereum Quorum and R3 Corda, could be executed alongside fiat-to-CBDC transactions with an RTGS system, through a unified gateway without compromising security or settlement finality.

Kaleido delivered full-stack infrastructure including the CBDC platform, middleware, and blockchain networks covering Ethereum Quorum and R3 Corda, along with application development and knowledge transfer. The solution featured a unified CBDC gateway to enable transactions across diverse DLT and RTGS systems. In collaboration with SWIFT and 18 central and commercial banks, the project executed CBDC-to-CBDC flows between Quorum and Corda as well as fiat-to-CBDC transactions with an RTGS system.