Interbank messaging platform SWIFT has published the results of a long-running distributed ledger proof-of-concept project.

Based on Hyperledger Fabric, the SWIFT trial focused on the use of nostro accounts, or bank accounts held by banks inside other banks. The proof-of-concept envisioned these “many-to-many” bank transfers, specifically examining how the system could meet requirements around governance, security and data privacy as they relate to the nostro reconcilitation process.

According to Damien Vanderveken, SWIFT’s head of research and development, the test provided a window into the strengths – and limits – of migrating such a system to distributed technology.

He said in a statement:

“The DLT sandbox enabled us to control access, to define and enforce user privileges, to physically segregate confidential data and store it only with the relevant parties while supporting a strong identity framework by linking all participants to their BIC, and having all keys signed by a SWIFT certification authority.”

“Lots of things we couldn’t do before, we can do now,” he later told CoinDesk. “Some things we couldn’t do, but it’s just a matter of time before they get fixed and we are entirely happy.”

According to Vanderveken, from a technology perspective, “the progress compared to a year ago was huge and fantastic.”

However, SWIFT’s report also details the limitations of the transaction capacities current blockchain solutions can support, considering that, at a commercial-scale level, the system in question would need to be able to handle many more channels than the proof-of-concept demonstrated.

“If you have so many channels, then it becomes more complicated to do a number of things,” Vanderveken explained.

That said, the test showed that banks could conduct real-time transactions using a distributed ledger, while staying in compliance with reporting requirements.

“It enabled real-time … transaction status updates, full audit trails, visibility of expected and available balances, real-time simplified account entries confirmation, the identification of pending entries and potential related issues, and generated the data required to support regulatory reporting,” Swift said.

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