Getting access to data

Masking personal data

Anonymising users using codes


Personal data is masked using a code to make it harder to trace it back to the individual, without the correct authorisation reveal the data. For example, a blood sample is labelled with a code, and only the doctor can work out who the blood came from by checking the code against a database.


  • Data can be processed without revealing who it relates to
  • If it gets lost it can’t be traced back to the individual


  • Large collections of pseudo-anonymous data can be de-anonymised, making it possible to identify people. In some cases differential privacy is recommended.