Beyond Data Silos: How TANGO Delivered Europe’s Federated Privacy Infrastructure

eco – Association of the Internet Industry is committed to strengthening Europe’s digital sovereignty through secure, open, and federated infrastructure. This mission underpins our engagement in strategic European projects that bridge policy and practice in digital innovation. One such initiative is the TANGO project, which exemplifies the application of these goals through real-world, cross-sector implementations.

Launched in late 2022 and concluded in August 2025, TANGO – Digital Technologies ActiNg as Gatekeepers to information flOws – gathered 36 partners across 14 countries with one mission: to engineer a platform that supports secure, interoperable, and sustainable data exchange across sectors and borders. This work wasn’t conducted in a vacuum. It is deeply embedded in the European strategy for a digital single market, aligned with frameworks like Gaia-X, the International Data Spaces Association (IDSA), and supported by the Data Spaces Support Centre (DSSC).

Bridging theory and practice: what makes a data space work?

Data spaces are not simply technology stacks – they are ecosystems governed by policy, supported by technical trust mechanisms, and driven by sectoral needs. A core element of TANGO’s design is the support for distributed infrastructure, which allows data to remain decentralized and under the control of its rightful owner.  This privacy-preserving architecture reinforces data sovereignty, a concept gaining momentum in European regulation.

TANGO’s use of the FIWARE Data Space Connector ensures that participants can interact through common protocols, while policy enforcement mechanisms control how data can be accessed or shared. This connector is compliant with the International Data Spaces Reference Architecture Model (IDS-RAM) and is already used to simulate cross-sector pilot scenarios.

Identity, privacy, and the value of self-sovereignty

One of the most innovative aspects of TANGO is the deep integration of Self-Sovereign Identity (SSI). Unlike traditional identity systems, SSI empowers individuals and organizations to manage their own verifiable credentials. Through the use of Verifiable Credentials stored in personal identity wallets, users can authenticate and authorize themselves without relying on a central authority. This is further strengthened by the deployment of distributed privacy-preserving Attribute-Based Credentials, a mechanism that employs Zero-Knowledge Proofs to verify attributes without revealing sensitive information.

These principles are not theoretical: they have been tested in live pilot projects. In the Smart Hospitality pilot project, for example, guests can check in using a digital identity stored in a mobile wallet, bypassing the need to present physical documents. Their preferences are interpreted by AI without exposing raw data, ensuring a high level of personalization while maintaining strict privacy standards. Similarly, in the Autonomous Vehicles pilot project, secure onboarding and permission-controlled access to proprietary virtual maps are handled through SSI-based credentials.

Making security operational

Security in TANGO is not just a technical feature – it is a governance model following a strict Security-by-Design approach.  Policies are articulated through the Open Digital Rights Language (ODRL), which defines data sharing conditions in a way that machines and humans alike can interpret. At runtime, these policies are enforced via access controls, tokenization, and encryption. For example, TANGO leverages AES 256-bit encryption and secure protocols such as HTTPS, SFTP, and MQTT for data transmission.

But what truly sets the project apart is its focus on continuous behavioral authentication. Rather than relying on static credentials, TANGO introduces adaptive systems that learn from user and device behavior over time. This approach leverages a number of behavioral traits – including device usage patterns, interaction histories, and even transactional rhythm – to detect anomalies proactively without burdening the user experience. This is not only an effective but also a scalable important factor in high-volume environments like banking and smart manufacturing.

Towards greener digital infrastructure

In parallel with its focus on sovereignty and trust, TANGO places strong emphasis on environmental sustainability. As the digital economy grows, so does its energy footprint. TANGO addresses this through multiple innovations.

First, an AutoML-based framework was developed to generate energy-efficient deep learning models. These models are trained in distributed environments, optimized for edge devices, and deliver high inference accuracy with minimal computational cost.

Second, through the integration of TornadoVM, applications written in Java could be dynamically recompiled for heterogeneous hardware such as GPUs and FPGAs. This enables energy-aware scheduling and execution, reducing power usage without compromising performance.

Finally, the application of AI for infrastructure management allows TANGO’s systems to be optimized in real time, balancing workload distribution across data centers based on energy consumption metrics.

Federated AI and explainability

With data sharing comes the imperative for AI that respects privacy. TANGO utilizes Federated Learning, where models are trained across decentralized datasets without exchanging raw data. This is especially powerful in sensitive domains like banking, where institutions can collaboratively train anti-fraud algorithms without exposing financial records. To complement this, TANGO develops Explainable AI (XAI) modules that provide context and reasoning behind AI-driven decisions.

Impact across sectors

TANGO is not merely a technical toolkit – it is a cross-sectoral infrastructure being piloted in six domains: smart hospitality, smart manufacturing, banking, autonomous vehicles, public administration, and retail. In each of these sectors, the project explores the tension between innovation and regulation, offering blueprints that other European initiatives can replicate.

 The path forward

TANGO has proven that Europe can lead in building data infrastructure that doesn’t force a choice between innovation and values. The project’s success across six sectors shows that federated, privacy-preserving data spaces aren’t just theoretical – they’re practical solutions ready for scale.

As global competition intensifies around data governance, Europe now has working blueprints that other regions are watching closely. TANGO’s combination of technical sovereignty, environmental consciousness, and user empowerment offers a compelling alternative to centralized data models.

For eco, this validates a core belief: Europe’s digital future should be built on openness, not ownership; on federation, not fragmentation. The real test now lies in adoption. TANGO may have concluded, but the movement it represents is just beginning.

Lauresha Memeti Toska is the Technical Project Manager for the Gaia-X Federation Services (GXFS) project in Germany, overseen by the eco – Association of the Internet Industry. With a background in Computer Science and Engineering, she actively contributes to project management and strategic development in areas such as Digital Business Models and Gaia-X, among others, within the eco Association.

Ladan Raeisian is a Junior Project Manager at eco – Association of the Internet Industry, where she supports projects that promote a safer and more innovative Internet, including TANGO. With a background in translation studies and linguistics, she is also part of the editorial team for dotmagazine, eco’s international online publication, where she develops and manages content on a wide range of Internet-related topics.