The New Backbone of Secure Financial Data Sharing

Jane Ginn

3 days ago

The regulatory landscape for secure financial data sharing is rapidly evolving, and with the CFPB’s Personal Financial Data Rights Rulemaking (PFDR), the need for robust, interoperable, and secure data standards has created a cyberspace race. The Financial Data Exchange (FDX) API v6.4.0 Consensus Standard Data Format (CSDF) emerges as a pivotal standard for U.S. Data Providers seeking to demonstrate compliance and deliver secure, user-permissioned data access. This article provides a technical overview into the CSDF, its requirements, security model, and practical implementation guidance for financial institutions and fintech developers.

What is the FDX CSDF?

The CSDF is a technical specification adopted by FDX—a CFPB-recognized standards body—defining the minimum requirements for a Data Provider’s developer interface to be considered conformant with a consensus standard under PFDR. The CSDF is designed to ensure that covered financial data is shared in a standardized, machine-readable, and secure format, facilitating interoperability across the open finance ecosystem.

Key Points:

Regulatory Alignment: The CSDF directly addresses PFDR’s requirement for standardized data sharing interfaces, providing a clear path for Data Providers to meet regulatory obligations.
Subset of FDX API: The CSDF is a curated subset of the broader FDX API Specification, focusing on resources and data elements most relevant to PFDR compliance, such as Regulation E accounts, Regulation Z credit cards, and digital wallets.
Versioning: CSDF v1.0 aligns with FDX API Spec v6.4.0 (and v5.4), ensuring up-to-date technical and security best practices.

Core Technical Requirements

1. API Schema Alignment

To achieve CSDF conformance, a Data Provider’s API must implement the “Applicable Resources” from the eligible FDX API specification versions (Core, Customers, Money-Movement, and Meta APIs). Key schema alignment requirements include:

Endpoints & Methods: Adherence to defined URL path patterns and HTTP methods (e.g., GET, POST).
Request Orchestration: Proper ordering, parameterization, and authorization for all data requests.
Response Formatting: Consistent use of JSON, standardized status codes, error handling, and pagination.
Data Structures: Strict alignment with FDX data entity definitions, types, and enumerations.
Component Reuse: Use of shared YAML components for schema definitions to ensure consistency and reduce duplication.

Reference List: The CSDF Reference List enumerates all data elements associated with covered account types (e.g., Reg E, Reg Z, digital wallets) and supporting technical elements (identifiers, error codes). Data Providers must share any subset of these elements in strict accordance with the technical formatting requirements.

2. API Security

Security is foundational to the CSDF. Data Providers must implement one of two approved security profiles for all relevant endpoints12:

Security Profile	Foundation	Key Features
Green	OAuth 2.0	Confidential clients, short-lived tokens, scope/audience restriction, secure token transmission, client certificate/privatekeyjwt auth
Blue	OIDF FAPI 2.0	Enhanced security controls, immediate token revocation on consent withdrawal, FAPI-compliant flows

Conditional Security Requirements:

Message Encryption: If required by agreement, payloads must use nested JWTs (JWS inside JWE), with robust key management (FIPS 140-2 level 3 or higher).
Step-up Authentication: For sensitive operations, OAuth 2.0 Step-up Authentication Challenge Protocol (RFC 9470) is supported.

3. Consent Management

While the initial CSDF version does not mandate a specific consent management protocol, FDX is actively developing standards for consent exchange, revocation, and authorization lifecycle management. Implementers should monitor future CSDF releases for updates in this area.

Lifecycle and Conformance

Conformance Validation

FDX provides a formal conformance test suite for Data Providers. This process validates:

Correct implementation of all shared data elements from the Reference List.
Adherence to schema, security, and formatting requirements.
Transparency regarding which fields were tested and passed.

Note: Conformance is format-based, not scope-based—Data Providers are not required to share all Reference List elements, only to format those they do share correctly.

Version Management

FDX intends to maintain both the full API specification and the CSDF as living standards, with clear versioning and deprecation timelines to ensure continued interoperability and regulatory alignment.

Developer Implementation Guidance

Best Practices:

Review the Full FDX API Spec: While CSDF conformance requires only a subset, familiarity with the broader specification enables more flexible and future-proof integrations.
Leverage Component YAMLs: Use shared schema components to streamline implementation and ensure consistency across endpoints.
Implement Robust Consent Flows: Even though not yet required by CSDF, following FDX’s user experience guidelines for consent journeys and dashboards enhances transparency and user trust.
Prioritize Security: Choose the security profile (Green or Blue) that best fits your risk model, and implement conditional requirements (encryption, step-up auth) as needed.
Plan for Change: Stay engaged with FDX and monitor updates to the CSDF and related security models to ensure ongoing compliance.

Conclusion

The FDX API v6.4.0 CSDF provides a clear, actionable path for Data Providers to achieve regulatory compliance and interoperability in the open finance era. By aligning with CSDF requirements, financial institutions and FinTech’s can deliver secure, user-centric data access while future-proofing their API strategies against evolving regulatory and market demands.

For organizations navigating the intersection of compliance, security, and innovation in financial data sharing, the CSDF is not just a technical standard—it’s a strategic imperative.

References:

Jane Ginn CTIN President & Co-Founder

Jane Ginn ~ As the co-founder of the US-based Cyber Threat Intelligence Network (CTIN), a consultancy with partners in Europe, Ms. Ginn has been pivotal in the development of the STIX international standard for modeling and sharing threat intelligence. She also served as the Secretary of the OASIS Threat Actor Context Technical Committee, contributing to the creation of a semantic technology ontology for cyber threat actor analysis. Her efforts in this area and her earlier work with the Cyber Threat Intelligence (CTI) TC earned her the 2020 Distinguished Contributor award from OASIS. She is currently supporting the analysis services of Datos Insights, an advisory firm focusing on the financial services sector. In public service, she advised five Secretaries of the US Department of Commerce on international trade issues from 1994 to 2001 and served on the Washington District Export Council for five years. In the EU, she was an appointed member of the European Union's ENISA Threat Landscape Stakeholders' Group for four years. A world traveler and amateur photojournalist, she has visited over 50 countries, further enriching her global outlook and professional insights.

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