Blockchain and the Future of Brazil's Financial System: Between Drex, Smart Contracts, and the AWS Cloud

Ever imagined having the same liquidity as a savings account, but for real estate, transferring digital shares of that asset with the same ease as sending a Pix payment? That's the kind of transformation blockchain promises to bring to the financial market and one that Bacen is already paving the way for with initiatives like Pix, Open Finance, and DREX.

What is Blockchain? Is it a snack or a drink?

The famous (and invisible) Nakamoto described blockchain as a record-keeping system based on distributed consensus, eliminating the need for a single "trusted entity" [Nakamoto, S. (2008). bitcoin: A peer-to-peer electronic cash system]

In practice, Blockchain is just a fancy name for a public, distributed ledger, where each page represents a block of transactions (Block), and each new page can only be written if it's mathematically linked to the previous one (chain) and approved by consensus. This structure makes the information immutable and transparent, once a transaction is recorded, it can't be altered without invalidating the entire sequence.

Okay, I just threw a bunch of "technical" stuff at you, and you probably didn't understand a word of it. So picture blockchain as the minutes book from your building's HOA meeting.

Every meeting gets recorded in the order it happened (block).
Every homeowner receives an identical copy of the minutes (network nodes).
To approve a new page, everyone has to agree on what's written (consensus).
If someone tries to alter an old page, everyone else notices immediately, because their copies no longer match.

The difference is that, on a Blockchain, this minutes book isn't kept in a folder or a drawer it's digitally distributed, protected by cryptography, and backed by signatures that guarantee the authenticity of every decision.

The technical detail behind the analogy:

The 'page' is the block;
The 'chaining' between pages is done through cryptographic hash functions.
The 'signature from every homeowner' is the consensus process (Proof of Work, Proof of Stake, Proof of Authority, etc.);
The 'unbreakable book' is the guarantee of immutability of the Ledger.

Notice that, in practice, the consensus process is the soul of blockchain.

And what does this have to do with me?

I just dumped a pile of information on you, and by now you might be wondering: so what's in it for me?

If you stop and think about it, the possibilities blockchain opens up are genuinely interesting, because it can reshape how you interact with money, data, and even the State itself. Its effects show up both as new conveniences and as new challenges. For example:

Financial inclusion: In developing countries, or countries at war, where millions of people don't have a bank account, blockchain would let you create a digital wallet accessible with nothing more than a phone or even by just memorizing a sequence of 24 words. That lowers the barriers to entry into the financial system.
Supply chain traceability: A company could track a raw material all the way from small producers to arrival at its own factory. Nestlé actually did this back in 2020: Nestlé Blockchain Case

Asset tokenization: Real estate, vehicles, and even artwork can be digitally fractionalized, letting people invest in assets at the level of fractions allowing anyone to invest in assets that used to be restricted to large investors.
More trust in public services: Subsidies like the gas voucher or Bolsa Família could be tied to smart contracts and paid out over blockchain networks, where everyone knows exactly where the money went with no room for it to get diverted along the way.

All of this also translates into real savings for the financial market. According to Don Tapscott, roughly 30% of banking back-office costs go purely into reconciling information between institutions. [Tapscott, D., & Tapscott, A. (2016). Blockchain Revolution]

So where does BACEN fit into this?

Bacen doesn't see blockchain as merely experimental innovation, but as strategic national infrastructure and that shows up in two products:

Pix (2020): Which, despite not using blockchain, proves the capacity to build nationwide-scale systems with instant settlement.
Drex: Which, despite not being our CBDC meaning it's the project behind Brazil's own digital-native currency is meant to serve:
- More efficient control of bank reserves;
- Atomic buying/selling of fractional government bonds;

In August 2025, at the Blockchain.Rio event, Bacen's current president (Galipolo) confirmed that DREX is not a CBDC ("as classic literature defines it") nor a stablecoin, but rather a tool for asset tokenization (also confirming that, at this stage, Bacen is not planning to actually use blockchain for it).

Okay. But what does AWS have to do with this?

When we think about how Bacen (or even a regional bank) could operate DREX to tokenize assets at national scale, the question isn't just which blockchain to use, but how do you sustain that infrastructure without drowning in cost and complexity?

This is where Amazon Managed Blockchain (AMB) comes in an AWS service that reduces the operational cost of putting blockchains into production, leveraging the power of EKS with KMS to serve as network nodes for other blockchains, since AMB supports Hyperledger Fabric, and Bacen is studying an implementation on Hyperledger Besu.

Up to this point I tried to keep things light on the jargon. Now, though, I'm flipping into full 'bit-scrubber' mode.

A Possible Solution for Bacen

Let's start with AMB itself: it's not simply "AWS's blockchain" it's a set of services that let you consume or create permissioned networks (Hyperledger Fabric), public networks (Ethereum/Polygon), and use AMB Query as a ready-made analytics layer to query transactions, balances, and history.

The advantage of using AMB for DREX would be distributed governance, private channels, and solid enterprise integration (hint, hint, Bacen). In fact, Hyperledger Fabric is the blockchain behind several CBDC projects, including DCash in the Caribbean, Aber in Saudi Arabia, Agila in the Philippines, and even Venus (a bond-tokenization project) in France.

Amazon Managed Blockchain

On AMB, beyond just creating permissioned networks, every participant (member) has a clearly defined and controlled role.

Core elements:

Network: the Fabric network, created on AMB, where the members live;
Members: the representation of a participating organization (for example Bank A, Bank B, Bacen). This is where the Peers and the CA run, and where governance is anchored.
Peer Nodes: Execute smart contracts (chaincode), validate transactions, and maintain the ledger.
Certificate Authority (CA): Issues the digital credentials that identify each participant/node.
Channels: Private sub-networks where only authorized members exchange transactions.

On top of that, integrating services like IAM (to define who can do what), KMS (which stores the cryptographic keys), and CloudTrail (audit logs) is straightforward.

A possible flow would be:

Bacen would create the Fabric Network on AMB and define the first Member;
- This member is responsible for setting governance policies (who can be invited, how chaincode gets approved, etc.).
Banks and fintechs would be invited to join the network as new members (via AMB);
- Each institution joins as a Member, with autonomy over its own nodes and identities.
Each member creates Peers to validate transactions and host chaincodes;
A CA on AMB generates certificates for admins, peers, and clients;
- Each member has its own CA, issuing certificates for:
  - Admins: who manage the network;
  - Peers: the validating nodes;
  - Clients/applications: an app that buys Treasury bonds, or that checks a bank reserve balance;
Channels are created, where sub-groups can exchange private information (e.g., settlement of tokenized assets).
- Here, Bacen could create private channels for interbank settlement;
- Another possibility would be creating asset tokenization on a channel restricted to fintechs;
The chaincode (smart contract) is deployed on the peers and starts governing the business logic;
- This is the cherry on top, where tokens get created (mint) and destroyed/settled (burn);
- Here, the sky's the limit you could program settlements, interbank transfers, and more;
Every transaction is signed, validated by the channel's peers, and recorded on the immutable ledger;

In short, if Bacen wanted to run a Drex pilot with governance distributed across banks, it could stand up the network on Hyperledger Fabric via AMB, while a private bank could, at the same time, use AMB Query to audit tokenized movements without maintaining any extra servers.

But why do it with AMB?

AMB's biggest advantage is being a managed service, and for Bacen and large banks and consortiums, AMB tends to strike a balance between governance + security + operations. For fintechs and PoCs, running on EKS/EC2 (or using public providers) buys agility and control, but comes with an operational cost, of course. Here's a cleaner comparison below:

Criteria	AMB	Self-managed node	Public network (Gnosis)
Operations	Fully managed (patching, HA)	You operate everything (high control)	100% outsourced
Security	IAM/KMS/VPC integrated	You define hardening/keys	Depends on the provider
Governance	Strong (ideal for consortiums/central banks)	Strong (if well implemented)	Variable
Performance/Latency	Good, but within the service's model	Maximum control (p2p tuning, disk, network)	Good, but without fine-grained guarantees
Cost	Per node/storage/requests	EC2/EBS/EKS/operational	Subscription/usage (egress/limits)
Interoperability	Fabric + supported public chains (Eth/Polygon)	Total (you choose the stack)	Good on public chains; provider lock-in
On-chain data (analytics)	AMB Query (serverless, multi-chain)	You index it yourself (TheGraph/ETL)	Some providers offer APIs

Conclusion

In the current landscape, Amazon Managed Blockchain (AMB) shows up as a strategic option for banks and fintechs that need to plug into the ecosystem quickly, without carrying the full weight of maintaining an entire infra stack (considering, of course, this is a hypothetical example used here).

AMB delivers:

Governance and compliance, ready out of the box;
On-demand scalability, without the complexity of Kubernetes clusters;
Direct integration with AWS services;

But there are limitations: adopting AMB means giving up some of the flexibility and independence that public networks or self-managed nodes on EKS allow. It's an inevitable trade-off between full control or speed with ready-made governance.

Ultimately, the critique is clear: the future of Drex, of the financial market, and of tokenization won't be defined by the technology it'll be defined by how Bacen, banks, and fintechs balance centralization and openness. Maybe the real challenge isn't choosing between Fabric, Besu, AMB, or EKS, but rather understanding when to use each approach.

original content: Blockchain e o Futuro do Sistema Financeiro Brasileiro: entre o Drex, Smart Contracts e a Nuvem da AWS
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