Audun Jøsang's homepage

Professor, Department of Informatics,  Security Group
University of Oslo
Adjunct Professor, QUT

Contact details
Department of Informatics, University of Oslo
PO Box 1080 Blindern
0316 Oslo, Norway
mob.: +47-98431433
email: josang@mn.uio.no
Audun Jøsang



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Research Interests

Identity Management is a crucial enabler for the development of online services. The problem with current identity management is that the solutions are designed to be practical from the service providers' point of view. These solutions do not scale, and provide poor usability for service consumers. A local user-centric approach is needed to make online service provision scalable for all.

Trust & Reputation Management for open computer networks includes developing trust and reputation systems that can assist users and organisations in assessing the trustworthiness of resources and remote parties on the Internet. Subjective Logic is compatible with Bayesian reputation systems, which provides a simple and elegant way of combining reputation systems with belief and trust reasoning.

Network Security has many dimensions such as communications and telecommunications security, network perimeter defence, wired/wireless/mobile network security, network protocol security, or semantics/trust-level and end-user interaction security. The latter is often defined in terms of ceremomy where the human context is integrated into network security models.

Security Usability is a crucial but largely ignored element in the security chain. People are often the weakest link in the security chain of systems and applications. This weakness is often amplified by poor security usability which leads to serious security vulnerabilities that can be exploited by hackers and criminals. The importance of security usability was already pointed out by the Belgian cryptographer Kerckhoffs in 1883.

Subjective logic is a type of probabilistic logic where arguments can contain degrees of uncertainty and where belief ownership can be explicitly expressed. Subjective logic is suitable for modelling and analysing situations characterised by uncertainty and incomplete knowledge, e.g. for modelling trust networks and Bayesian networks. A rich set of operators makes subjective logic flexible and applicable for modelling practical situations.


Audun Jøsang is professor in cybersecurity at the University of Oslo. He holds a Master's degree in Information Security from Royal Holloway College, University of London, and a PhD from NTNU in Norway. Before joining the University of Oslo, Prof. Jøsang worked as Associate Professor at QUT in Australia, as telecommunications engineer for Alcatel in Belgium and for Telenor in Norway. His research focuses on cybersecurity threat intelligence, trusted computing, identity & access management, and reasoning under uncertainty with subjective logic. Prof. Jøsang acts as the Norwegian national representative to IFIP TC-11.

Last updated: 9 April 2018