Christian Johansen

About

See my homepage https://christian.johansenresearch.info/

Do you want to be a Teaching Assistant (TA) this autumn semester in one of the courses IMT4123 or IIKG2001 ? Send me an e-mail!

I am head of the Systems Security group, which we just call S2G, and am part of the CCIS (Center for Cyber and Information Security), the Norwegian Cyber Range, and the S2G Playground.

I work in Theoretical Computer Science focusing on developing and using formal methods and tools for ensuring reliability of complex systems, including properties regarding security, safety, and concurrency. Applications of such methods are numerous, e.g., verification of safety properties of software systems (like absence of certain bugs) or of hybrid systems like the Smart Grids, ensuring security of Internet of Things, or modelling the concurrency of modern multi-core or high-performance computing. Among methods or models that I have created I can list: the Timed Distributed pi-calculus, the ST-structures, the Dynamic Structural Operational Semantics, the Synchronous Kleene Algebra, or the Higher Dimensional Modal Logic. Together with my students I have worked on developing tools, e.g., together with Manish Shrestha we made the LightSC Security Classification Method for Smart Grids and IoT and the associated usable security tool with the same name; whereas together with Bjørnar Luteberget we made the SAT modulo Discrete Event Simulation method and tool applied to railway capacity verification. A nice and long collaboration with Tore Pedersen has taken me also into the realm of modelling of human behaviour, where some of my contributions are: proposing the Behavioural Computer Science agenda, where models of human behaviour are combined with CS models of system behaviour (execution); or the probabilistic modelling of humans in security ceremonies.

I have done research in different areas of computer science, including modelling of security protocols; (object-oriented) programming languages and their formal semantics; modelling languages and verification of networked systems; models and tools for parallel programming and concurrent systems; algebras and logics as used in computer science; timed process calculi for distributed and mobile communicating systems; (legal) electronic contracts and privacy agreements (ToS -- Terms of Services). My work, more than 45 international articles, has been published in highly ranked conferences s.a. CONCUR, ATVA, LFCS, FM, POST, or CCS, and top journals s.a. JLAMP, IJCIP, FMSD, or LMCS. More recent works usually target concurrency, security, and privacy. I finished my doctoral studies in 2010 at University of Oslo and have been involved ever since in teaching and supervision, in reviewing for international conferences and journals, in the organisation of conferences and workshops, and in the coordination and writing of projects submitted to highly competitive calls, s.a.: EU-FP7-FET-Young-Explorers, Horison-2020, NFR-FRINATEK, UK’s EPSRC, ECSEL-JU.

Research

Systems Security Group (S2G)

Publications

2022

Arshad, Hamed; Horne, Ross; Johansen, Christian; Owe, Olaf; Willemse, Tim A. C.. (2022) Process Algebra Can Save Lives: Static Analysis of XACML Access Control Policies Using mCRL2. Formal Techniques for Distributed Objects, Components, and Systems. 42nd IFIP WG 6.1 International Conference, FORTE 2022, Held as Part of the 17th International Federated Conference on Distributed Computing Techniques, DisCoTec 2022, Lucca, Italy, June 13–17, 2022, Proceedings.
Academic chapter/article
Arshad, Hamed; Johansen, Christian; Owe, Olaf. (2022) Semantic Attribute-Based Access Control: A review on current status and future perspectives. Journal of systems architecture. volum 129.
Scientific translation/review
Arshad, Hamed; Johansen, Christian; Owe, Olaf; Picazo-Sanchez, Pablo; Schneider, Gerardo. (2022) Semantic Attribute-Based Encryption: A framework for combining ABE schemes with semantic technologies. Information Sciences.
Academic article
Aubert, Clement; Horne, Ross; Johansen, Christian. (2022) Diamonds for Security: A Non-Interleaving Operational Semantics for the Applied Pi-Calculus. Leibniz International Proceedings in Informatics. volum 30.
Academic article
Fahrenberg, Uli; Johansen, Christian; Struth, Georg; Ziemiański, Krzysztof. (2022) A Kleene Theorem for Higher-Dimensional Automata. Leibniz International Proceedings in Informatics. volum 243.
Academic article
Fahrenberg, Uli; Johansen, Christian; Struth, Georg; Ziemiański, Krzysztof. (2022) Domain Semirings United. Acta Cybernetica. volum 25 (3).
Academic article
Fahrenberg, Uli; Johansen, Christian; Struth, Georg; Ziemiański, Krzysztof. (2022) Posets with interfaces as a model for concurrency. Information and Computation. volum 285.
Academic article
Aubert, Clement; Horne, Ross; Johansen, Christian. (2022) Bisimulations Respecting Duration and Causality for the Non-interleaving Applied Pi-Calculus. Electronic Proceedings in Theoretical Computer Science (EPTCS). volum 368.
Academic article
Johansen, Johanna; Pedersen, Tore; Fischer-Hübner, Simone; Johansen, Christian; Schneider, Gerardo; Roosendaal, Arnold; Zwingelberg, Harald; Sivesind, Anders Jakob; Noll, Josef. (2022) A multidisciplinary definition of privacy labels. Information and Computer Security. volum 30 (3).
Academic article

2021

Calk, Cameron; Fahrenberg, Uli; Johansen, Christian; Struth, Georg; Ziemiański, Krzysztof. (2021) lr-Multisemigroups, Modal Quantales and the Origin of Locality. Lecture Notes in Computer Science (LNCS). volum 13027.
Academic article
Fahrenberg, Uli; Johansen, Christian; Struth, Georg; Ziemiański, Krzysztof. (2021) Languages of higher-dimensional automata. Mathematical Structures in Computer Science. volum 31 (5).
Academic article
Fahrenberg, Uli; Johansen, Christian; Trotter, Christopher A.; Ziemiański, Krzysztof. (2021) Sculptures in concurrency. Logical Methods in Computer Science. volum 17 (2).
Academic article
Johansen, Christian; Aulon, Mujaj; Arshad, Hamed; Noll, Josef. (2021) The Snowden Phone: A Comparative Survey of Secure Instant Messaging Mobile Applications. Security and Communication Networks.
Scientific translation/review
Johansen, Johanna; Noll, Josef; Johansen, Christian. (2021) InfoInternet for education in the Global South: A study of applications enabled by free information-only internet access in technologically disadvantaged areas. African Journal of Science, Technology, Innovation and Development (AJSTID).
Academic article
Johansen, Johanna; Pedersen, Tore; Johansen, Christian. (2021) Studying human-to-computer bias transference. AI & Society: The Journal of Human-Centred Systems and Machine Intelligence.
Academic article
Luteberget, Bjørnar Steinnes; Claessen, Koen; Johansen, Christian; Steffen, Martin. (2021) SAT modulo discrete event simulation applied to railway design capacity analysis. Formal methods in system design. volum 57.
Academic article
Luteberget, Bjørnar Steinnes; Johansen, Christian. (2021) Drawing with SAT: four methods and A tool for producing railway infrastructure schematics. Formal Aspects of Computing. volum 33.
Academic article

2020

Shrestha, Manish; Johansen, Christian; Noll, Josef; Roverso, Davide. (2020) A Methodology for Security Classification applied to Smart Grid Infrastructures. International Journal of Critical Infrastructure Protection. volum 28.
Academic article
Fahrenberg, Uli; Johansen, Christian; Struth, Georg; Thapa, Ratan Bahadur. (2020) Generating Posets Beyond N. Lecture Notes in Computer Science (LNCS). volum 12062.
Academic article
Shrestha, Manish; Johansen, Christian; Moghadam, Maunya D.; Johansen, Johanna; Noll, Josef. (2020) Tool Support for Security Classification for Internet of Things (long version). Universitetet i Oslo. 2020. ISBN 978-82-7368-460-8.
Report
Shrestha, Manish; Johansen, Christian; Noll, Josef. (2020) Building Confidence using Beliefs and Arguments in Security Class Evaluations for IoT (long version). Universitetet i Oslo. 2020. ISBN 978-82-7368-458-5.
Report
Tokas, Shukun; Owe, Olaf; Johansen, Christian. (2020) Code Diversification Mechanisms for Internet of Things (Revised Version 2). 2020. ISBN 978-82-7368-438-7.
Report

2019

Hildebrandt, Thomas; Johansen, Christian; Norman, Håkon. (2019) A stable non-interleaving early operational semantics for the pi-calculus. Journal of Logical and Algebraic Methods in Programming. volum 104.
Academic article
Johansen, Christian; Owe, Olaf. (2019) Dynamic Structural Operational Semantics. Journal of Logical and Algebraic Methods in Programming. volum 107.
Academic article
Johansen, Christian; Owe, Olaf. (2019) Summary of: Dynamic Structural Operational Semantics. Lecture Notes in Computer Science (LNCS). volum 11918.
Academic article
Luteberget, Bjørnar Steinnes; Claessen, Koen; Johansen, Christian. (2019) Automated Drawing of Railway Schematics Using Numerical Optimization in SAT. Lecture Notes in Computer Science (LNCS). volum 11918 LNCS.
Academic article
Luteberget, Bjørnar; Johansen, Christian; Steffen, Martin. (2019) Synthesis of railway signaling layout from local capacity specifications. Lecture Notes in Computer Science (LNCS). volum 11800 LNCS.
Academic article
Pedersen, Tore; Johansen, Christian. (2019) Behavioural artificial intelligence: an agenda for systematic empirical studies of artificial inference. AI & Society: The Journal of Human-Centred Systems and Machine Intelligence.
Academic article
Shrestha, Manish; Johansen, Christian; Noll, Josef. (2019) Criteria for Security Classification of Smart Home Energy Management Systems (long version). Universitetet i Oslo. 2019. ISBN 978-82-7368-457-8.
Report

2018

Noll, Josef; Garitano, Iñaki; Johansen, Christian; Del Ser, Javier; Arenaza-Nuno, Ignacio. (2018) Perspectives in Secure SMART Environments. Measurable and Composable Security, Privacy, and Dependability for Cyberphysical Systems : The SHIELD Methodology.
Academic chapter/article
Pedersen, Tore; Johansen, Christian; Jøsang, Audun. (2018) Behavioural Computer Science: an agenda for combining modelling of human and system behaviours. Human-centric Computing and Information Sciences. volum 8:7.
Academic article

2017

Bursuc, Sergiu; Johansen, Christian; Xu, Shiwei. (2017) Automated verification of dynamic root of trust protocols. Lecture Notes in Computer Science (LNCS). volum 10204 LNCS.
Academic article
Hildebrandt, Thomas; Johansen, Christian; Normann, Håkon. (2017) A stable non-interleaving early operational semantics for the Pi-calculus. Lecture Notes in Computer Science (LNCS). volum 10168 LNCS.
Academic article
Johansen, Christian; Mujaj, Aulon; Arshad, Hamed; Noll, Josef. (2017) Comparing Implementations of Secure Messaging Protocols (long version). Universitetet i Oslo. 2017. ISBN 978-82-7368-440-0.
Report
Luteberget, Bjørnar Steinnes; Camilleri, John J.; Johansen, Christian; Schneider, Gerardo. (2017) Participatory Verification of Railway Infrastructure Regulations using RailCNL (long version). 2017. ISBN 978-82-7368-430-1.
Report
Luteberget, Bjørnar Steinnes; Camilleri, John J.; Johansen, Christian; Schneider, Gerardo. (2017) Participatory verification of railway infrastructure by representing regulations in RailCNL. Lecture Notes in Computer Science (LNCS). volum 10469 LNCS.
Academic article
Luteberget, Bjørnar Steinnes; Johansen, Christian. (2017) Efficient verification of railway infrastructure designs against standard regulations. Formal methods in system design. volum 52 (1).
Academic article
Shrestha, Manish; Johansen, Christian; Noll, Josef. (2017) Security Classification for Smart Grid Infra structures (long version). Universitetet i Oslo. 2017. ISBN 978-82-7368-441-7.
Report
Tokas, Shukun; Owe, Olaf; Johansen, Christian. (2017) Code Diversification Mechanisms for Securing the Internet of Things. Proceedings of the 29th Nordic Workshop on Programming Theory.
Academic chapter/article

2016

Johansen, Christian. (2016) ST-structures. Journal of Logical and Algebraic Methods in Programming. volum 85 (6).
Academic article
Johansen, Christian; Jøsang, Audun; Migdal, Denis. (2016) Offpad: Offline personal authenticating device: implementations and applications. 2016. ISBN 978-82-7368-419-6.
Report
Johansen, Christian; Jøsang, Audun; Migdal, Denis. (2016) Usable Authentication with an Offline Trusted Device Proxy Architecture (long version). 2016. ISBN 978-82-7368-418-9.
Report
Johansen, Christian; Norman, Håkon; Hildebrandt, Thomas. (2016) Non-interleaving Operational Semantics for the Pi-calculus -- technicalities. Universitetet i Oslo. 2016. ISBN 978-82-7368-416-5.
Report
Johansen, Christian; Pedersen, Tore; Jøsang, Audun. (2016) Reflections on Behavioural Computer Science. 2016. ISBN 978-82-7368-417-2.
Report
Johansen, Christian; Pedersen, Tore; Jøsang, Audun. (2016) Towards Behavioural Computer Science. IFIP Advances in Information and Communication Technology. volum 473.
Academic article
Luteberget, Bjørnar Steinnes; Johansen, Christian; Feyling, C; Steffen, Martin. (2016) Rule-based incremental verification tools applied to railway designs and regulations. Lecture Notes in Computer Science (LNCS). volum 9995 LNCS.
Academic article
Luteberget, Bjørnar Steinnes; Johansen, Christian; Steffen, Martin. (2016) Rule-Based Consistency Checking of Railway Infrastructure Designs. Universitetet i Oslo. 2016. Conference proceedings (Universitetet i Oslo. Institutt for informatikk) (450).
Report
Luteberget, Bjørnar Steinnes; Johansen, Christian; Steffen, Martin. (2016) Rule-based consistency checking of railway infrastructure designs. Lecture Notes in Computer Science (LNCS). volum 9681.
Academic article
Migdal, Denis; Johansen, Christian; Jøsang, Audun. (2016) DEMO: OffPAD - Offline Personal Authenticating Device with Applications in Hospitals and e-Banking. Proceedings of the 2016 ACM SIGSAC Conference on Computer and Communications Security.
Chapter
Normann, Håkon; Johansen, Christian; Hildebrandt, Thomas. (2016) Declarative event based models of concurrency and refinement in psi-calculi. Journal of Logical and Algebraic Methods in Programming. volum 85 (3).
Academic article

2015

Johansen, Christian; Jøsang, Audun. (2015) Probabilistic Modeling of Humans in Security Ceremonies. Data Privacy Management, Autonomous Spontaneous Security, and Security Assurance: 9th International Workshop, DPM 2014, 7th International Workshop, SETOP 2014, and 3rd International Workshop, QASA 2014, Wroclaw, Poland, September 10-11, 2014. Revised Selected Papers.
Academic chapter/article
Johansen, Christian; Jøsang, Audun. (2015) Probabilistic modelling of humans in security ceremonies. Lecture Notes in Computer Science (LNCS). volum 8872.
Academic article
Taherkordi, Amirhosein; Johansen, Christian; Eliassen, Frank; Römer, Kay. (2015) Tokenit: Designing State-Driven Embedded Systems through Tokenized Transitions. Distributed Computing in Sensor Systems (DCOSS).
Academic chapter/article

Part of book/report

Arshad, Hamed; Horne, Ross; Johansen, Christian; Owe, Olaf; Willemse, Tim A. C.. (2022) Process Algebra Can Save Lives: Static Analysis of XACML Access Control Policies Using mCRL2. Formal Techniques for Distributed Objects, Components, and Systems. 42nd IFIP WG 6.1 International Conference, FORTE 2022, Held as Part of the 17th International Federated Conference on Distributed Computing Techniques, DisCoTec 2022, Lucca, Italy, June 13–17, 2022, Proceedings.
Academic chapter/article
Noll, Josef; Garitano, Iñaki; Johansen, Christian; Del Ser, Javier; Arenaza-Nuno, Ignacio. (2018) Perspectives in Secure SMART Environments. Measurable and Composable Security, Privacy, and Dependability for Cyberphysical Systems : The SHIELD Methodology.
Academic chapter/article
Tokas, Shukun; Owe, Olaf; Johansen, Christian. (2017) Code Diversification Mechanisms for Securing the Internet of Things. Proceedings of the 29th Nordic Workshop on Programming Theory.
Academic chapter/article
Migdal, Denis; Johansen, Christian; Jøsang, Audun. (2016) DEMO: OffPAD - Offline Personal Authenticating Device with Applications in Hospitals and e-Banking. Proceedings of the 2016 ACM SIGSAC Conference on Computer and Communications Security.
Chapter
Johansen, Christian; Jøsang, Audun. (2015) Probabilistic Modeling of Humans in Security Ceremonies. Data Privacy Management, Autonomous Spontaneous Security, and Security Assurance: 9th International Workshop, DPM 2014, 7th International Workshop, SETOP 2014, and 3rd International Workshop, QASA 2014, Wroclaw, Poland, September 10-11, 2014. Revised Selected Papers.
Academic chapter/article
Taherkordi, Amirhosein; Johansen, Christian; Eliassen, Frank; Römer, Kay. (2015) Tokenit: Designing State-Driven Embedded Systems through Tokenized Transitions. Distributed Computing in Sensor Systems (DCOSS).
Academic chapter/article

Report

Shrestha, Manish; Johansen, Christian; Moghadam, Maunya D.; Johansen, Johanna; Noll, Josef. (2020) Tool Support for Security Classification for Internet of Things (long version). Universitetet i Oslo. 2020. ISBN 978-82-7368-460-8.
Report
Shrestha, Manish; Johansen, Christian; Noll, Josef. (2020) Building Confidence using Beliefs and Arguments in Security Class Evaluations for IoT (long version). Universitetet i Oslo. 2020. ISBN 978-82-7368-458-5.
Report
Tokas, Shukun; Owe, Olaf; Johansen, Christian. (2020) Code Diversification Mechanisms for Internet of Things (Revised Version 2). 2020. ISBN 978-82-7368-438-7.
Report
Shrestha, Manish; Johansen, Christian; Noll, Josef. (2019) Criteria for Security Classification of Smart Home Energy Management Systems (long version). Universitetet i Oslo. 2019. ISBN 978-82-7368-457-8.
Report
Johansen, Christian; Mujaj, Aulon; Arshad, Hamed; Noll, Josef. (2017) Comparing Implementations of Secure Messaging Protocols (long version). Universitetet i Oslo. 2017. ISBN 978-82-7368-440-0.
Report
Luteberget, Bjørnar Steinnes; Camilleri, John J.; Johansen, Christian; Schneider, Gerardo. (2017) Participatory Verification of Railway Infrastructure Regulations using RailCNL (long version). 2017. ISBN 978-82-7368-430-1.
Report
Shrestha, Manish; Johansen, Christian; Noll, Josef. (2017) Security Classification for Smart Grid Infra structures (long version). Universitetet i Oslo. 2017. ISBN 978-82-7368-441-7.
Report
Johansen, Christian; Jøsang, Audun; Migdal, Denis. (2016) Offpad: Offline personal authenticating device: implementations and applications. 2016. ISBN 978-82-7368-419-6.
Report
Johansen, Christian; Jøsang, Audun; Migdal, Denis. (2016) Usable Authentication with an Offline Trusted Device Proxy Architecture (long version). 2016. ISBN 978-82-7368-418-9.
Report
Johansen, Christian; Norman, Håkon; Hildebrandt, Thomas. (2016) Non-interleaving Operational Semantics for the Pi-calculus -- technicalities. Universitetet i Oslo. 2016. ISBN 978-82-7368-416-5.
Report
Johansen, Christian; Pedersen, Tore; Jøsang, Audun. (2016) Reflections on Behavioural Computer Science. 2016. ISBN 978-82-7368-417-2.
Report
Luteberget, Bjørnar Steinnes; Johansen, Christian; Steffen, Martin. (2016) Rule-Based Consistency Checking of Railway Infrastructure Designs. Universitetet i Oslo. 2016. Conference proceedings (Universitetet i Oslo. Institutt for informatikk) (450).
Report

Teaching

Courses

Supervision

For MSc thesis topics, contact me directly before the start of the second year.

Media

2018

Academic lecture

Karami, Farzane; Owe, Olaf; Schneider, Gerardo; Johansen, Christian. (2018) The Future Mechanism and Information Flow Security. The 30th Nordic Workshop on Programming Theory, Oslo ; 2018-10-24 - 2018-10-26.

2017

Lecture

Pedersen, Tore; Johansen, Christian; Jøsang, Audun. (2017) Intelligence Analysis: Reflections on the Future Human - Machine Analytic Enterprise from a Behavioral Computer Science Perspective. AF Security Seminar Series . University of Oslo, Department of Informatics; Oslo. 2017-06-16 - 2017-06-16.
Academic lecture

Tokas, Shukun; Owe, Olaf; Johansen, Christian. (2017) Code Diversification Mechanisms for Securing the Internet of Things. 29th Nordic Workshop on Programming Theory (NWPT'17) . Åbo University; Turku. 2017-11-01 - 2017-11-03.

2012

Academic lecture

Prisacariu, Cristian. (2012) The Glory of the Past and Geometrical Concurrency. The Alan Turing Centenary Conference (Turing-100) ; Manchester. 2012-06-18.

2009

Academic lecture

Okika, Joseph; Owe, Olaf; Prisacariu, Cristian. (2009) Operational Semantics for BPEL Complex Features in Rewriting Logic. 21. Nordic Workshop on Programming Theory (NWPT'09) . Technical University of Denamrk; Lyngby. 2009-10-14 - 2009-10-16.
Academic lecture

Prisacariu, Cristian. (2009) Synchronous Kleene Algebra vs. Concurrent Kleene Algebra. Young Researchers Workshop on Concurrency Theory (YRCONCUR09) . Joost-Pieter Katoen; Bologna. 2009-09-05 - 2009-09-05.

Språkvelger

Christian Johansen