Progress Report on Bank of Japan Retail CBDC Experiments (BoJ)
The Bank of Japan (BoJ) published an English version of the progress report on its retail central bank digital currency (CBDC) experiments published in Japanese in June 2026. It finds that no fatal technical barriers preclude a full-scale launch, yet severe scalability and resource challenges remain unresolved in the current prototyping phase. The architecture is based on a two-layered model that decouples a centralized core ledger for basic accounting from a peripheral layer of privately managed overlay services. By linking application programming interfaces on the central bank’s core to diverse external systems, private intermediaries tested various innovations, including distributed ledger technology platforms for purpose-bound money and tokenized securities settlement. Although simulations processed 50,000 transactions per second, they were significantly simplified compared to real-world demands. The proposed record-splitting solution for single-account transaction concentration exhibited diminishing returns, as excessive splitting degraded performance. Furthermore, the application sandbox operated separately from the centralized high-load pilot system, leaving unresolved how cross-layer latency, asynchronous transaction failures, and ledger synchronization between the core and external systems will perform under live retail market stress. Also, despite the simplified architecture, resource consumption proved substantial, raising critical questions about the feasibility of the massive system resources required for national deployment. [BoJ]
Sixth General Meeting of the Bank CBDC Forum (BoJ)
The BoJ also published a summary of the sixth general meeting of its CBDC Forum that provided a condensed executive presentation of the technical findings detailed in progress report above. It also announced that the Forum’s seven working groups were being reorganized into three discussion groups focused on retail CBDC architecture, new technologies, and retail CBDC ecosystems. The new technologies group will evaluate stablecoins, tokenized deposits, distributed ledger technology, asset tokenization, and programmability. Furthermore, the restructured Forum will operate with a focus on initiatives that also contribute to the BoJ’s efforts related to wholesale payment systems. [BoJ]
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