An in-depth explanation regarding the security surrounding statistical linkage keys, why they’re important and how their security can be compromised…
The security of the Australian 2016 Census has sparked much debate and consternation among privacy advocates and security professionals alike. At the core of these concerns is a move by the Australian Bureau of Statistics (the ABS) to start linking census records to other data. The mechanism proposed for linking records and data is a ‘random looking’ Statistical Linkage Key. We have been told that the linkage key is secure and will be ‘hashed’ to make it irreversible – but what exactly does that mean, and how does it secure your data?
Introducing the Statistical Linkage Key
Statistical Linkage Keys or SLKs have been used frequently by people doing data research, it provides some very basic anonymity, and a sanity check on the data while retaining a way of identifying an individual throughout a study.
The Australian Bureau of Statistics publishes a standard called the SLK581 cluster. It defines a method for turning “Jane Smith 01/01/2007 Female” in to random looking serial number like “MIHAN010120072”. Continue reading