In the eighth of a series of posts on the General Data Protection Regulation (GDPR), which comes into force from May 25th, 2018, I’m looking at what GDPR has to say about pseudonymisation.
Here’s what you need to know:
What is pseudonymisation?
The GDPR defines pseudonymisation as “the processing of personal data in such a way that the data can no longer be attributed to a specific data subject without the use of additional information.” But you must hold the pseudonymised data and the additional information separately, to prevent possible identification. This is because the data only becomes identifiable when both elements are held together.
There is an important distinction between pseudonymisation and another term used heavily in GDPR – anonymisation, which means making it impossible to connect personal data to an identifiable person. Truly anonymised data (very difficult to achieve) is exempt from the laws of GDPR.
What are the advantages of pseudonymised data?
GDPR permits you to use pseudonymised personal data more liberally, as there is little risk of infringing the rights of data subjects. For example, it is exempt from some requirements of GDPR, such as portability and the right to erasure. GDPR also allows pseudonymised data to be used beyond the purpose for which the data was originally collected, something it ordinarily prohibits. So, along as you pseudonymise it, you can use data for a number of purposes, rather than just your original intention.
Basically, by pseudonymising data you allow yourself a lot more leeway in how it is used and have less responsibilities in regards the person you originally collected the data from.
With pseudonymised data, unlike truly anonymous data, you face the risk of reidentification – either by way of a data breach, or through some malicious detective work. Under GDPR this would put you in the firing line, so you must ensure that additional information (which, combined with pseudonymised data, could reveal identities) is secure and encrypted.
• Pseudonymisation means processing personal data to make it unidentifiable without the use of additional information
• Pseudonymised data can be used more freely
• You must take steps to prevent the risk of reidentification