  As organisations expand and interconnect, authorisation infrastructures
become increasingly difficult to manage. Several solutions have been proposed,
including self-adaptive authorisation, where the access control policies are
dynamically adapted at run-time to respond to misuse and malicious behaviour.
The ultimate goal of self-adaptive authorisation is to reduce human
intervention, make authorisation infrastructures more responsive to malicious
behaviour, and manage access control in a more cost effective way. In this
paper, we scope and define the emerging area of self-adaptive authorisation by
describing some of its developments, trends and challenges. For that, we start
by identifying key concepts related to access control and authorisation
infrastructures, and provide a brief introduction to self-adaptive software
systems, which provides the foundation for investigating how self-adaptation
can enable the enforcement of authorisation policies. The outcome of this study
is the identification of several technical challenges related to self-adaptive
authorisation, which are classified according to the different stages of a
feedback control loop.
