Ensuring adequate security of the personal data collected is a major task on the part of personal data controllers. There are many data protection techniques, and they include data anonymization and pseudonymization. In the following article you will learn what these techniques are and whether they can be used interchangeably.
Data protection techniques
According to the RODO, personal data protection should apply to any information about identified, or modifiable, individuals. The controller, when processing personal data, should provide full protection against identifying that person from his or her data. The controller decides for himself what protection technique he wants to use. He makes the decision after a risk analysis. Anonymization and pseudonymization of data are two important provisions, but it should be remembered that they cannot be used interchangeably for the same purpose. The administrator should choose which method he will use already in the design phase.
Pseudonymization of personal data
Pseudonymization is one of the technical and organizational measures that enhance data security. It is most simply defined as the processing of personal data in such a way that it cannot be attributed to a specific person without the use of additional information. This technique limits the possibility of associating a particular set of personal data with a person’s true identity, so that the controller can make it difficult to identify that person. Pseudonymization involves altering personal data to make it impossible to attribute it to a specific individual. For example, an administrator can encrypt the data with a special “key.” However, the Data Protection Authority points out that the encrypted data and the key cannot be transmitted through the same information channel. Pseudonymization of data is an effective method of protection, but it should be borne in mind that it is still possible to indirectly identify a person.
Anonymization of personal data
The provisions of the RODO do not contain a definition of “anonymization of personal data.” We can define it as the irreversible process of making it impossible to define a person. This data protection technique should be used by controllers when there is a need to permanently remove from data carriers any information that could identify individuals (e.g. name, address, phone number). Once personal data has been anonymized, there is virtually no other way for the administrator to re-disclose the deleted data.
Differences between anonymization and pseudonymization
Note that pseudonymization is not an anonymization technique. The main feature that distinguishes the two methods is reversibility. Pseudonymization is reversible, while the anonymization process is irreversible. In addition, the controller using the anonymization method makes it impossible to identify that person, so the RODO cannot be applied to the processing of such data. In conclusion, the moment a personal data controller would like to ensure irreversible exclusion of access to data, it should opt for the use of the anonymization technique. For ongoing protection of processed data, pseudonymization is the best method.
Source:
DPA Newsletter for Data Protection Officers No. 4/2021(25) April 2021