What is what - Pseudonymisation vs Anonymisation

Pseudonymisierung vs Anonymisierung im Datenschutz

What is it about?

Navigate the complex world of data protection with a clear understanding of two often misunderstood terms: pseudonymisation and anonymisation. Learn how they differ from each other and what they mean for the protection of personal data.

In the data protection world, there are many terms thrown around. Two of them are pseudonymisation and anonymisation. Although these terms are often used interchangeably, there is a big difference. The following explains what the two terms mean and how they differ.


‍Pseudonymisation involves replacing personal data with artificial identifiers, also called pseudonyms. This can be done in various ways, the most common being to replace names with unique IDs. The purpose of pseudonymisation is that personal data can no longer be associated with a specific person without the use of a key.


‍In anonymisation, on the other hand, personal data is completely removed from the data. What remains is a data set that can no longer be associated with a specific person. The main difference is that pseudonymised data can still be traced back to a person if you have the right key, whereas this is not possible with anonymised data.

How are they used?

‍Pseudonymisation and anonymisation are both commonly used techniques for data protection compliance. Which technique you use depends on a number of factors, including what kind of data you are dealing with and how sensitive it is. If you are dealing with data that is not particularly sensitive - for example, publicly available information such as addresses or contact information - pseudonymisation may be sufficient. If, on the other hand, you are dealing with more sensitive data, e.g. health data or financial data, full anonymisation may be necessary to protect the privacy of individuals. It should also be noted that pseudonymisation is not foolproof: if someone gets hold of your pseudonymisation key, he or she can link the pseudonymised data to individual persons. For this reason, it is often used in combination with other security measures such as strict access restrictions.


In conclusion, pseudonymisation and anonymisation are two important but different techniques for data protection compliance. Which technique you use depends on the type of data you are working with and how sensitive it is. For less sensitive data, pseudonymisation usually provides sufficient protection; however, for more sensitive data, full anonymisation may be necessary to protect individuals' privacy.

Additional advice

If, despite these explanations, you are still unclear or in doubt, it is always a good idea to consult a data protection officer. These experts are specially trained to advise on such complex issues and can ensure that you choose the best method to comply with data protection regulations.

With the support of a data protection officer, you can safely navigate through the maze of data protection regulations and make the right decisions for your business or organisation.‍

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