Information security at payment institutions: from regulatory compliance to architecture

Information security at a payment institution (IP) covers the traceability of every transaction, precise control over who accesses what, and the ability to preserve or restore essential services during security incidents. In 2025, Pix, Brazil’s instant payment system, recorded almost 80 billion transactions, according to the Central Bank of Brazil. For anyone operating at that volume, every weak point has a direct impact on business continuity.

Consider a hypothetical scenario: the treasury team at a company with 2,000 suppliers discovers that a payment batch went out approved by a user without approval authority for that amount, because of a poorly configured access setting. Fixing it may require reviewing access rights, the approvals already made and the related records.

Conversations about information security at fintechs and IPs tend to focus on external attacks. Risks related to excessive permissions, shared credentials, unauthenticated webhooks and improper data handling can go unnoticed until an incident or an audit happens.

Payment security must be built into the architecture

In a payments operation, the decision about who can access what, in which context and with what level of authorization, must be settled before the first integration goes into production. That decision determines how the rest of the system behaves.

A payments API that exposes transaction data carries, by definition, a policy on who can call it and what they get back. When that policy is part of the architecture from the start, it applies to every integration by default: the client connects its application and already operates within a defined security perimeter. Each new integration starts from a consistent base of controls, complemented by the specific settings of each client and flow.

Approval rules, which define who can approve a given operation based on amount, responsibility or configured flow, follow the same logic. When designed as part of the approval flow, they act as a built-in barrier: the system holds the payment until the condition is met, with no need for manual verification steps.

This design has a direct effect on the blast radius of any security failure. In a system with architectural controls, an unauthorized actor using a compromised credential operates within the same boundaries as the original profile. Least-privilege controls help limit the blast radius by restricting possible actions to the scope assigned to the compromised credential.

What high-volume operations expect beyond regulatory compliance

The Central Bank of Brazil sets security and continuity requirements for payment institutions: system availability, incident response capability and failure recovery. These criteria define the minimum standard for regulated operation.

For Pix specifically, the BCB maintains the IQS (Pix Service Quality Index, Índice de Qualidade de Serviço do Pix), which rates participating institutions on indicators such as service availability, complaint rate and timeouts. The top rating signals that the institution operates within the strictest stability parameters.

In high-volume B2B operations, operational requirements go beyond what regulation sets:

• Declared uptime with a verifiable track record.
• Native webhooks with authentication and automatic retries on failure.
• API credentials restricted to pre-registered IP addresses.
• Separation between view, execution and approval profiles.
• An auditable log of every action taken within the account.

A proper audit trail should make it possible to identify the action, the user, the time, the result and the context of the operation.

Access configuration as a risk vector

Identity and access risks begin before any external attack. In many cases, they are already present in the permission structure from the moment the account is set up.

In financial operations, the principle that governs this problem is straightforward: each person on the team should have access to exactly what their role requires. In practice, something else often happens: permissions granted at onboarding and never reviewed as the person’s role changes, profiles shared among several users for operational convenience, or departed employees who keep active access because of gaps in the offboarding process.

Each of these patterns creates a risk vector with different consequences:

• Permissions beyond the role: an analyst with an execution profile who doesn’t use that permission day to day is an active attack surface. If their credentials are compromised, the attacker operates with execution scope within the account.
• Shared credentials: when two users operate with the same login, any action recorded in the system loses individual authorship. In an audit, assigning individual responsibility becomes impossible to do reliably.
• Active user after termination: without structured offboarding, the former employee retains access while the company doesn’t notice. In operations with high turnover, access can remain active until the gap is identified and fixed.

Each of these patterns has a complementary control. Least-privilege profiles reduce excessive permissions, ensuring each user operates only within the scope of their role. Individual accounts prevent credential sharing and preserve authorship of every action in the system. This granularity creates individual traceability for every action and protects the team itself in case of a dispute: each decision can be tied to the user who made it, as long as individual logins and tamper-proof records are used.

Three fundamental layers for control and traceability

Platforms that take security seriously structure the problem in three layers with distinct functions:

Authentication verifies the identity the user presents; authorization determines which actions they can take; and auditing records what was done.

They are three layers with distinct functions, which is why they must work together. When one of them is missing or misconfigured, the entire chain of traceability is compromised.

Trio structures user control into profiles with approval limits by amount and by type of operation, and every action within the account generates a traceable record. Transaction events and status updates can be sent in real time through configurable, authenticated webhooks, so the client’s system reflects the current state of the account without relying on manual exports.

Why Trio supports the security community

No company solves security on its own. Real progress in the industry happens when researchers, practitioners and companies openly share knowledge about vulnerabilities, techniques and architectures.

That is the purpose of the BSides conferences, a global network of information security events that began in Las Vegas in 2009. As of July 2026, the global organization had counted 1,329 events held in 300 cities across 73 countries. BSides arrived in Brazil in 2011 and spread to São Paulo, Rio de Janeiro, Florianópolis, Vitória and João Pessoa. In 2025 alone, the Brazilian events brought together more than 2,300 participants.

Talk proposals come in through a public call and are selected by the event organizers, which helps keep the agenda connected to the topics and challenges that drive the technical community. The result is an environment for technical depth and hands-on exchange: researchers presenting vulnerabilities, Blue Team and Red Team practitioners trading methodologies, and CISOs and governance and security professionals discussing risk management.

Trio at BSides CWB: October 17, 2026, Curitiba

On October 17, 2026, Curitiba hosts the first edition of BSides CWB, held at PUCPR (Pontifical Catholic University of Paraná). The program includes mini-trainings, technical talks, themed villages (CISO, Forensics, BioHacking, Lockpicking, Cloud, Blue Team, Red Team, Women in Security and more), a Capture the Flag (CTF) competition, and a track of educational and recreational activities just for kids.

Trio will be there as an event sponsor, reinforcing its ties to the security community. For a payment institution authorized and supervised by the Central Bank of Brazil, information security is part of what defines operational quality. And operational quality depends on an ecosystem that constantly updates itself, with professionals in ongoing contact with the latest techniques and vulnerabilities.

Events like BSides CWB build that ecosystem. For Trio, taking part is a way to share the same space as the professionals who are building the practices and discussions that move security forward in the industry.

If you’ll be in Curitiba on the 17th, BSidesCWB takes place at PUCPR. More information at bsidescwb.com.br.

Information security as part of the operation

Information security in payments is the sum of architectural decisions that determine whether the operation holds up under pressure, whether access is controlled with real granularity, and whether every transaction can be reconstructed for operational purposes, audits and requests from the competent authorities.

For Trio, which operates as a payment institution authorized and supervised by the Central Bank of Brazil, this set of decisions underpins the ability of a high-volume operation to run predictably. Events like BSides CWB are where that standard keeps being built, through exchange among the professionals on the front lines of digital security.

To learn how Trio structures access control and traceability in B2B operations, talk to our team.