Soda Labs

Brazil

A named anonymity rule, and a CBDC that could not solve privacy

JurisdictionAmericasAttribution required

A regulated firm must be able to attribute activity to an identified person, and assets or accounts that make that impossible are barred at the licensed perimeter. This is a rule about attribution, not about whether amounts are public.

What Brazil actually says

Brazil holds the two halves of this section's argument in one place. Its listing rule is among the most explicit anywhere, requiring providers to bar assets designed to favour money laundering by facilitating anonymity, while the same framework expressly contemplates a client choosing self-custody and asks only that the provider explain the risks. Then there is Drex. The central bank spent a pilot phase testing zero-knowledge designs precisely to build confidentiality into a state currency, and reported that the approaches which delivered privacy also cost it the visibility and control it judged necessary for its legal obligations. That is the trilemma stated by a central bank from its own experiment rather than argued in the abstract, and it is the most honest public account of the problem we found.

The instruments that matter

Resolutions BCB 519, 520 and 521 of 10 November 2025
create the virtual asset service provider framework, covering authorisation, operation, and virtual asset services in the foreign exchange market
Resolution 520, Article 64
listing policies must prohibit offering virtual assets with characteristics that favour fraud or crime, expressly including assets designed to favour money laundering and terrorist financing by facilitating anonymity
Self-custody expressly permitted
Article 57 contemplates a client choosing self-custody, with the provider's duty being to explain the necessary security measures rather than to refuse
Travel rule with wallet identification
Article 44 requires originator and beneficiary information including identification of the transaction's virtual asset wallet
Drex could not reconcile privacy with oversight
the central bank tested zero-knowledge approaches including Anonymous Zether and Rayls, and found that stronger anonymisation cost it the visibility and control it considered necessary

What this means for confidential transactions

Bubble is built for exactly this shape of obligation: amounts and balances live on chain as ciphertexts, computation happens without decryption, and the only disclosure path is an on-chain access list through which an authorized party - an auditor, a supervisor, a counterparty - can request scoped decryption. That is confidentiality from the public, not from the regulator.

Compliant by default.

See how selective disclosure satisfies a supervisor without publishing your book to the world.