Differential Privacy – Privacy-preserving data analysis

It is widely known that tech companies, like Apple or Google and their partners collect and analyse an increasing amount of information. This includes information about the person itself, their interaction and their communication. It happens because of seemingly good motives such as:

  • Recommendation services: e.g. word suggestions on smartphone keyboard
  • Customizing a product or service for the user
  • Creation and Targeting in personalised advertising
  • Further development of their product or service
  • Simply monetary, selling customer data (the customer sometimes doesn’t know)

In the process of data collection like this clients’ or users’ privacy is often at risk. In this case privacy includes confidentiality and secrecy. Confidentiality means that no other party or person than the recipient of sent message can read the message. In the special case of data collection: no third party or even no one else but the individual, not even the analysing company should be able to read its information to achieve proper confidentiality. Secrecy here means that individual information should be kept secret only to the user.

Databases may not be simply accessible for other users or potential attackers, but for the company collecting the data it probably is. Despite anonymization/pseudonymization, information can often be associated to one product, installation, session and/or user. This way conclusions to some degree definite information about one very individual can be drawn, although actually anonymized or not even available. Thus, individual users are identifiable and traceable and their privacy is violated.

The approach of Differential Privacy aims specifically at solving this issue, protecting privacy and making information non-attributable to individuals. It tries to reach an individual deniability of sent/given data as a right for the user. The following article will give an overview of the approach of differential privacy and its effects on data collection.

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