Security & GDPR

Data clean rooms: collaborating without exposing data

What a data clean room is, how it lets parties gain value from their combined data without sharing it directly, and its use cases.

DLData Layer Team May 18, 2025 4 min read
Data clean rooms: collaborating without exposing data

Key takeaways

  • A data clean room lets parties analyse combined data without exposing raw data.
  • Each party keeps control of its own data.
  • It is key in advertising, banking and inter-company collaboration.
  • It relies on access control, aggregation and privacy by design.
  • For simple cases, an anonymised dataset may suffice.

Sometimes two companies could generate enormous value by combining their data — measuring shared audiences, detecting fraud, comparing results — but neither can or should hand its raw data to the other. Data clean rooms resolve that paradox.

What it is

A data clean room is a secure, controlled environment where two or more parties combine and analyse their data to obtain joint results, without any of them accessing the others’ raw data.

How it works

Party A
Its dataisolated
Clean room
IsolatedOnly allowed analyses
Party B
Its dataisolated
Result
JointNo raw data
In a clean room, each party contributes data to an isolated environment that returns only aggregated results.

Each party’s data is loaded into an isolated, governed environment where only certain analyses are allowed, usually over aggregated or anonymised data. The joint result is shared; individual data is not.

Use cases

Privacy by design and when not to use them

The key is that privacy is built in: strict control of allowed queries, minimum aggregation to avoid re-identification, and access traceability. But clean rooms are not universal: they require agreements and governance, and for a simple, one-off exchange an anonymised or synthetic dataset may suffice. They shine when collaboration is recurring and data sensitive.

A clean room lets parties collaborate with data without any of them losing control of their own.

In summary

A data clean room is a secure environment where parties combine and analyse data for joint results without exposing raw data — key in advertising, banking and collaboration. It relies on access control, aggregation and privacy by design, and shines when collaboration is recurring; for simple cases, anonymised data may be enough.

Sources & further reading

Frequently asked questions

What is a data clean room?

A secure environment where several parties combine and analyse data for joint results without any accessing the others’ raw data.

What are they used for?

Advertising, fraud detection, sector benchmarks or research: cases where combining data adds value but sharing it directly is not viable.

Are they GDPR-compliant?

Well designed, yes: they apply access control, aggregation and traceability to gain value without exposing personal data.

How do they work inside?

Each party loads data into an isolated environment that only allows certain analyses over aggregated or anonymised data, returning the result, not the data.

Are they always the best option?

No. They need agreements and governance; for simple cases an anonymised or synthetic dataset may suffice. They shine in recurring collaborations with sensitive data.

Who uses them?

Advertising (shared audiences), banking and insurance (fraud and risk), and groups comparing results without revealing their own data.

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