Disputation: Hamed Arshad

Doctoral candidate Hamed Arshad at the Department of Informatics, Faculty of Mathematics and Natural Sciences, is defending the thesis Toward Semantic Attribute-Based Access Control: Fine-grained protection of data in e-Health for the degree of Philosophiae Doctor.

Picture of the candidate

Photo: Private

The PhD defence will be partially digital, in Kristen Nygaards sal (5370), Ole-Johan Dahls hus and streamed directly using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the attending audience at Kristen Nygaards sal to ask ex auditorio questions. 

Trial lecture

“Blockchain-based access control models”

Friday December 2nd, 2022, 10:15 AM, Kristen Nygaards sal (5370), Ole-Johan Dahls hus / Zoom


Main research findings

  • This dissertation first conducts a systematic literature review to analyze conducted research efforts on Semantic Attribute-Based Access Control (SABAC). Then, it proposes a Semantic Attribute-Based Encryption (SABE) framework, which is modular, generic, scalable, and extensible. Accordingly, two semantic-aware attribute-based encryption (ABE) schemes are proposed by augmenting an ABE scheme with semantic technologies. Next, the dissertation proposes Attribute-Based Encryption with enforceable OBligations (OBABE), a system for extending any classical ABE with enforceable obligations. In order to bring obligations in ABE schemes, a formal language for the specification of obligations and a system architecture having Intel Software Guard Extensions (SGX) as the core component for enforcing obligations are provided. Finally, this dissertation presents a methodology for formal verification of access control policies based on the mCRL2 process algebra. The presented methodology is supported by a tool, XACML2mCRL2, that automatically transforms policies into formal specifications.

Adjudication committee:


  • Associate Professor Melek Önen, EURECOM, France     
  • Professor Vladimir Oleshchuk, University of Agder, Norway
  • Associate Professor Amirhosein Taherkordi, University of Oslo, Department of Informatics, Norway


  • Professor Christian Johansen, Norwegian University of Science and Technology (NTNU)
  • Professor Olaf Owe, Department of Informatics, University of Oslo


Chair of defence:

Associate Professor Ragnhild Kobro Runde

Candidate contact information:  https://www.linkedin.com/in/hamedarshad/

Contact information at Department: Mozhdeh Sheibani Harat

Published Nov. 18, 2022 9:00 AM - Last modified Dec. 1, 2022 1:13 PM