Anonymisation software

Province of Zeeland

The algorithm underlines personal data in documents. An employee has to look at all the pages and check whether the document is properly anonymised. Then the software removes all underlined information and varnishes it. After that, the documents can be published, for example under the Open Government Act.

Last change on 14th of January 2025, at 15:11 (CET) | Publication Standard 1.0

• Publication category: Impactful algorithms
• Impact assessment: Field not filled in.
• Status: In use

General information

Theme

Organisation and business operations

Begin date

2022-08

Contact information

[e-mail]

Responsible use

Goal and impact

The anonymisation software is used to anonymise documents published by the Province of Zeeland faster and better. This way, we prevent data leaks and contribute to better protection of data subjects' AVG rights.

Considerations

The Province of Zeeland increasingly has to make information public. Therefore, privacy or business-sensitive information has to be masked out. The advantage of the anonymisation software is that anonymisation is faster and better than with a manual approach.

Human intervention

The outcome of the algorithm is checked by an employee. The clerk is required by the software to check all pages. The clerk determines whether the document is correctly anonymised.

Risk management

There is no risk of automated decision-making and the algorithm has no impact on fundamental rights because the algorithm does not make decisions with legal consequences. It only suggests anonymising personal data. If the algorithm does not work well enough, we can make adjustments with black- and whitelists. The employee of Province of Zeeland always does the final test of whether a document has been anonymised correctly.

Legal basis

1. WOO 2. WCO 3. UAVG 4. WEP 5. WDO

Links to legal bases

• Woo: https://wetten.overheid.nl/BWBR0045754/
• WDO: https://eur-lex.europa.eu/legal-content/NL/TXT/HTML/?uri=CELEX:31995L0046
• UAVG: https://wetten.overheid.nl/BWBR0040940
• Wep: https://wetten.overheid.nl/BWBR0043961
• Wdo: https://wetten.overheid.nl/BWBR0048156

Operations

Data

All information found in the uploaded documents (except metadata) is processed by the algorithm. This may include ordinary personal data, special personal data and criminal data. It may also include business-sensitive information.

Technical design

Documents are uploaded to the application by an employee. At that point, a (temporary) copy is made of the original in the form of a PDF with text layer and the metadata of the original document is removed from the copy. This copy ends up on a Dutch server and remains there for a maximum of 30 days. The text layer of the PDF is offered to the machine learning algorithm through an API. This is a Natural Language Processing algorithm (named entity recognition) from Microsoft Azure. The API returns at which location in the analysed texts a personal data is likely to occur, along with the probability score (a percentage). At that point, Azure immediately removes the text layer. The probability score is used along with vendor-developed proprietary ai models to make the recognition of personal data as accurate as possible. The models are trained with trained datasets. Finally, an employee checks the document and when they finalise the document, the data to be anonymised is permanently removed from the text layer and varnished.

External provider

XXLLNC Anonymise