Data minimization
Each department gets the copy it needs: resident identities are no longer in it.
Public sector
Pseudonymize before you share, by design
Resident case files, incident reports, tracking spreadsheets:
NymData pseudonymizes sensitive files before they move between departments.
Staff work on the copy.
Original files stay on your servers, restricted to authorized staff.
Before: identifiable residents, in red
| Resident | Date of birth | Address | Request |
|---|---|---|---|
| Emily Brooks | 09/14/1979 | 42 Cedar Lane | Housing assistance |
| John Carter | 05/02/1981 | 1428 Elm Street | School enrollment |
| Emily Brooks | 09/14/1979 | 42 Cedar Lane | Paratransit service |
Shared as is, the spreadsheet exposes every resident
After: constant identifier, requests kept
| Resident | Date of birth | Address | Request |
|---|---|---|---|
| PERSON_7b94f21c | [DATE] | [ADDRESS] | Housing assistance |
| PERSON_3e1a9d02 | [DATE] | [ADDRESS] | School enrollment |
| PERSON_7b94f21c | [DATE] | [ADDRESS] | Paratransit service |
Same resident, same identifier: tracking still works
- Pseudonymized copy for staff
- Originals for authorized staff only
- Role-based access
- Audit report for your privacy officer
How do you apply data protection by design (privacy by design)?
By sharing only the data each use actually needs.
With NymData, installed on your own servers, sensitive files are pseudonymized before they are shared between departments.
Staff work on a copy where each resident is replaced by a constant identifier, for example PERSON_7b94f21c.
Original files stay restricted to authorized staff.
Every run is documented in an audit report.
The principle
Internal sharing is still sharing
A file sent to another department, an elected official or a working group gets forwarded, copied and archived.
Data protection by design means sharing only what is necessary, a principle the GDPR makes mandatory.
Role-based access
Administrator, operator, auditor: each person sees what their role allows.
Original files never leave your servers.
Traceability
Every run produces a timestamped, sealed audit report you can attach to your records of processing activities.
Documents covered
What public agencies protect
The files that move most often between departments.
- Tracking spreadsheets in Excel or CSV: requests, benefits, enrollments. Excel and CSV
- Letters and reports in Word or PDF: incident reports, memos, committee minutes. PDF
- Presentations for boards, councils and working groups. PowerPoint
- Line-of-business databases on PostgreSQL or MySQL, copied to a reporting database. Databases
Use cases
When should you anonymize this data?
Sharing between departments
Send a case file or a spreadsheet without resident identities.
Statistics and reporting
Build indicators from pseudonymized data, with each resident still tracked by their identifier.
Contractors and vendors
Provide realistic data for an IT project or a test database.
Archives
Keep the value of older data beyond its retention period, in anonymized form.
Framework
What the GDPR says
GDPR Article 25 requires data protection by design and by default: process only the data needed for each purpose.
Pseudonymization is named there as an appropriate measure.
Pseudonymized data is still personal data.
For wide distribution or publication, you need effective anonymization, after assessing the re-identification risk with your privacy officer.
Which method should you choose? · Pseudonymization vs anonymization: what is the difference?
Scope
What NymData handles for you
- SupportedOn your own servers
- Installed on your premises or in your data center: nothing is sent outside.
- SupportedRole-based access
- Auditors review reports and logs without seeing document content.
- SupportedConstant identifier
- The same resident gets the same identifier in every Word, Excel and CSV file of the project.
- SupportedTraceability
- Every run produces a timestamped, sealed audit report.
FAQ
Frequently asked questions
Can staff still access the original data?
Only authorized staff can: NymData creates a pseudonymized copy in a separate folder and never changes the original files, which stay on your servers with their usual access rights.
Can we track the same resident across several files?
Yes. With the constant identifier method, the same resident gets the same code in every Word, Excel and CSV file of the project: counts and follow-up remain possible without knowing who they are.
Is any data sent outside?
No. NymData is installed on your own servers.
No data or telemetry is sent to NymData or to any cloud service.
What is data protection by design?
It is a requirement of GDPR Article 25: design processing so that it uses only the data it needs.
Pseudonymizing a file before sharing it is a direct application of it.
How do we prove what was processed?
Every run produces a timestamped, sealed audit report: data types detected, method applied, volumes.
You can attach it to your records of processing activities.
See NymData pseudonymize a tracking spreadsheet, live
Live demo on sample files, remotely or at your site.