Can I Use Data De-Identification to Secure My Data?

As a business owner, you will have legal obligations to secure the data you hold. Here, it is crucial that you meet these obligations so that your customers feel confident in providing you with their data. If you do not properly store data, you heighten the risk of your business facing a data breach and someone stealing sensitive information about your customers. This article explains what your legal obligations may be surrounding how de-identification of data can assist you in meeting these obligations and mitigating risk to your business.

What Are My Legal Obligations on Securing Data?

Privacy Law Obligations

In Australia, there is a core federal privacy law which may apply to your business, called the Privacy Act. This law only applies in certain situations, including, notably, where a business has an annual turnover of over $3 million. 

Your business must comply with the Privacy Act if you have:

• an obligation for the security of the personal information you hold;
• a limitation on how long you can store identifiable data for; and
• notification obligations for some types of data breaches.

The obligation for the security of the personal information you hold requires that you take reasonable steps to protect the personal information from: 

• misuse;
• interference;
• loss;
• unauthorised access; or
• modification.

The limitation on how long you store identifiable data for states that you should:

• not hold personal information for any longer than the period that you need it;
• only use it for permitted purposes; or 
• not disclose personal information to unauthorised parties.

Data breach obligations require that you notify both the regulator and the affected individual if the data breach would likely result in serious harm to them. When considering this, you should take into account the context of the breach when making this assessment, like the:

• number of people who accessed the breached data;
• sensitivity of the data; and
• quantity of data.

Contractual Obligations

You may also have contractual obligations to secure data. 

Can De-Identification of Data Help?

De-identification of data can have a significant role in meeting the legal obligations described above. De-identifying data involves altering the data in a way which hides the identity of the person that the data relates to.

De-identification is beneficial as:

• it can protect personal information and therefore can help you meet your security obligations;
• you can use it instead of disposing of the data, as a means of making sure you do not hold data past its legal storage limit; and
• it limits the likelihood that a data breach will cause serious harm to any of the individuals that the personal information relates to.

It is crucial to highlight that if you are de-identifying data instead of disposing of it, the risk of that information being re-identified should be very low.

What Are the De-Identification Options?

If you use de-identification as a means to assist in securing your data, you will need to consider whether your intention is to: 

• anonymise the data; or
• pseudonymise the data. 

Where you anonymise the data, you should reduce it to a state where it is very unlikely that someone will be able to re-identify it, even if the data is paired with another source of information.

Pseudonymisation, however, is a lesser form of de-identification. This is because pseudonymisation only requires that the data set is not identifiable by itself, but can be identified if paired with other data.

Encryption is a common form of pseudonymisation. Encryption works by making text appear as code until a secret key is used to unlock the text. Another technique to pseudonymise data is to store the data sets in separate locations so that each data set may only be used to identify an individual if it is combined with a data set in another location.

Key Takeaways

De-identifying data is a useful tool for securing your data. You may wish to secure data to satisfy your legal obligations under Australian privacy law and any contracts you have with customers. When you choose to de-identify data, you will need to consider whether to anonymise or pseudonymise it. This will depend on the purpose of de-identifying it and what you wish to use the data for. If you have any questions about d-identifying data, contact LegalVision’s privacy lawyers on 1300 544 755 or fill out the form on this page.