Datamask - Anonymisation tool

Municipality of Bergeijk

Datamask is a computer programme that helps make personal data unrecognisable. It does this automatically according to fixed rules. In this way, data is well protected. The municipality of Bergeijk uses Datamask when information is shared with others or when working with data internally, without needing anyone's name or address.

Last change on 12th of June 2025, at 14:29 (CET) | Publication Standard 1.0

• Publication category: Impactful algorithms
• Impact assessment: DPIA
• Status: In use

General information

Theme

Organisation and business operations

Begin date

05-2025

Contact information

[e-mail]

Link to publication website

https://bergeijk.nl/toegankelijkheid

Responsible use

Goal and impact

Personal data is protected by making it unrecognisable. This happens when the data is reused, for example for policies, reports or open data sharing.

Considerations

Gemeente Bergeijk uses Datamask because it is important to protect personal data properly. The tool works quickly and helps prevent errors. This keeps residents' privacy more secure. Possible disadvantages, such as too much or too little anonymisation, are controlled with proper settings and training. The advantages outweigh the disadvantages, so use is fair and appropriate

Human intervention

An employee of the Bergeijk municipality uses the Datamask results to check whether all personal data has been properly removed. If not, the employee can adjust it. The employee can also change the settings of the programme so that it works better next time. In this way, a human always remains involved in checking and improving the result.

Risk management

The Bergeijk municipality takes a close look at Datamask risks, such as accidentally leaving personal data or deleting too much information. To prevent this, checks are done. Employees receive explanations and training on how to use the tool properly. Settings are also regularly checked and adjusted if necessary. In this way, the Bergeijk municipality ensures that the tool continues to work safely and well.

Legal basis

The municipality of Bergeijk must comply with the law when working with personal data. According to the Privacy Act (AVG), this data must be properly protected. That is why the municipality of Bergeijk uses Datamask to make data unrecognisable. The Open Government Act (Woo) also plays a role, because the municipality of Bergeijk sometimes has to share information with others. With Datamask, this can be done safely, without revealing personal data.

Links to legal bases

• Algemene Verordening Gegevensbescherming (AVG) Artikel 5 AVG: Beginselen inzake verwerking van persoonsgegevens: https://eur-lex.europa.eu/legal-content/NL/TXT/HTML/?uri=CELEX:32016R0679&qid=1685451198313
• Wet open overheid (Woo) Regeling Wet open overheid – recht op informatie openbaar maken: https://wetten.overheid.nl/BWBR0045754/2023-04-01

Link to Processing Index

https://cuatro.sim-cdn.nl/bergeijk/uploads/Register%20van%20verwerkingen%20gemeente%20Bergeijk%202024.pdf?cb=Qyj3PO_8

Impact assessment

Data Protection Impact Assessment (DPIA)

Operations

Data

Datamask uses texts from documents containing personal data, such as names, addresses, dates of birth, phone numbers, e-mail addresses and citizen service numbers (BSN). This data is recognised and then rendered unrecognisable. When creating the tool, common ways in which these data appear in documents were considered so that Datamask can find and remove them properly.

Technical design

Datamask is a computer programme that automatically makes personal data in documents unrecognisable. The programme searches the text for things like names, addresses and BSN numbers. If it finds such data, Datamask replaces it with a standard text, such as "First name Last name" or "1234 XX". This way, the data remains protected. An employee can check the result and adjust it if necessary.

External provider

https://xxllnc.nl/applicaties/anonimiseren