ISSN : 1796-217X
Volume : 3    Issue : 1    Date : January 2008

Implicit Authorization for Social Location Disclosure
Georg Treu, Florian Fuchs, and Christiane Dargatz
Page(s): 18-26
Full Text:
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Being increasingly equipped with highly-accurate positioning technologies, today’s mobile phones
enable their owners to transmit their current position over the cellular network and share it with
others. So-called location-based community services make use of this possibility, for example for
locating friends, co-workers or family members. Of course, these services give target persons
control about the way location data may be accessed by others. So far, this is done by the target
explicitly granting or denying permissions through authorization policies or ad-hoc authorization.
Unfortunately, apart from bringing along high management effort, the concept of explicit
authorization in such a privacy-sensitive application entails the disadvantage of social difficulties.

In this paper we introduce the concept of implicit authorization, which has reciprocity as its central
element: Another person is granted access to a certain target’s location information implicitly by the
target accessing the information of that other person as well. The technique aims to reduce social
pressure on the target person when deciding whether a certain person may locate her or not. Also,
the target person is relieved from management overhead. Several realizations of implicit
authorization are proposed. They differ in the service pattern (reactive/proactive) they are useful for
and the way a once given access grant is revoked.

Index Terms
community LBS, proactive LBS, social disclosure, authorization, reciprocity, ambiguity