Banco Central do Brasil completed the first phase of its CBDC pilot project, revealing key aspects of the Drex architecture, privacy and programmability features, and highlighting major technological challenges.
Banco Central do Brasil (BCB) reported the results of the first stage of the Drex pilot, which took place from July 2023 to October 2024. During this phase, two types of digital assets were tested:
- Drex de Atacado — for interbank settlements;
- Drex de Varejo — for retail payments.
Additionally, tokenized government bonds, Título Público Federal Tokenizado (TPFt), were issued to test the delivery versus payment (DvP) scenario, allowing the evaluation of data protection mechanisms, decentralization, and programmability.
The tests involved more than 420 transactions with Drex de Atacado tokens, 1,900 transactions with Drex de Varejo, and 1,263 successful transactions with TPFt. The pilot involved 16 consortiums, bringing together over 100 financial institutions, including banks, payment service providers, blockchain devs, and financial market infrastructure operators.
The pilot tested several privacy-enhancing technologies, including Prova de Conhecimento Zero (ZKP), Anonymous Zether, Rayls, and Microsoft Nova ZKP. The system architecture, based on Hyperledger Besu, was also tested using the Quorum Byzantine Fault Tolerant (QBFT) consensus model. To strengthen Drex network resilience, 26 nodes were deployed, interconnected via Brazil’s National Financial System Network (RSFN).
The report highlights the need for further improvements in data protection mechanisms to fully comply with Brazil’s Banking Secrecy Law (Lei Complementar 105/2001) and General Data Protection Law (LGPD, Lei 13.709/2018).
Drex entered the second phase of the pilot, where 13 use case scenarios are being tested, including digital asset transactions and smart contract applications.
