The Bank of Japan has released a progress report on its pilot program for a central bank digital currency (CBDC). The report outlines the design characteristics of the system for the pilot program and explains the end-to-end process flow. The bank conducted performance tests on the system, including a single-account concentration test and a mixed workload test, to evaluate its performance requirements. The results showed that the system can process a total load of 50,000 transactions per second (TPS), combining 10,000 TPS of update transactions and 40,000 TPS of balance inquiry transactions. However, the test also revealed the need to address significant latency increases associated with processing spikes. The bank identified the importance of controlling the number of incoming requests per unit time to the request intake points of the customer management system and ledger management system to handle processing spikes. The report also discusses various functions and use cases related to credit transfers, including destination information management, reverse transaction processing, and security measures. The bank examined the possibility of an alternative process flow for credit transfer, which prioritizes the prior securing of funds necessary for the credit transfer. The report highlights the need to design the overall system architecture, taking into account various functional and non-functional requirements, and to perform appropriate sizing while remaining mindful of the efficiency of server and network resources. The bank also emphasizes the importance of ensuring system security, including the use of post-quantum cryptography and migration to such cryptography, anticipating future realization of large-scale and practical quantum computers.