  With the ubiquitous use of location-based services, large-scale
individual-level location data has been widely collected through
location-awareness devices. The exposure of location data constitutes a
significant privacy risk to users as it can lead to de-anonymisation, the
inference of sensitive information, and even physical threats. Geoprivacy
concerns arise on the issues of user identity de-anonymisation and location
exposure. In this survey, we analyse different geomasking techniques that have
been proposed to protect the privacy of individuals in geodata. We present a
taxonomy to characterise these techniques along different dimensions, and
conduct a survey of geomasking techniques. We then highlight shortcomings of
current techniques and discuss avenues for future research.
