Swedish Institute of Computer Science Publications Database
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New Paradigms for Authorization and Access Control in Constrained Environnements
No full textThe Internet of Things (IoT) is here, more than 10 billion units are already connected and five times more devices are expected to be deployed in the next five years. Technological standarization and the management and fostering of rapid innovation by governments are among the main challenges of the IoT. However, security and privacy are the key to make the IoT reliable and trusted. Security mechanisms for the IoT should provide features such as scalability, interoperability and lightness.
This paper adresses authentication, authorization and access
control in the frame of the IoT. It describes two technologies which, used in conjunction, provide all the credentials for secure authorization and access control in wireless constrained hardware systems with scalability and interoperability requirements. Physical Unclonable Functions (PUF) are lightweight cryptographic primitives that can be easily embedded in reconfigurable hardware. They provide secure, low-cost authentication means for constrained devices. Embedded Subscriber Identity Module (eSIM) provide cellular connectivity with scalability, interoperability and standard compliant security protocols. An authorization scheme involving a client, an authorization server and a constrained resource server is proposed based on PUF and eSIM features. Concrete IoT uses cases are discussed (SCADA and building automation)
Environmental Comfort Design Considerations for Future Control Room Interiors
No full textToday, there is a significant amount of research projects focusing on human health and well-being and the connection between the environment and human psychological responses. Perceived comfortable environments have a strong connection with humans when sensory communication and socio-cultural aspects are included in the design. Here, comfort is seen as an achievement not an attribute. Holistic approaches are emerging to integrate operators, control room communications and well-being with comfortable interiors. This paper illustrates the shifting focus of environmental design to environmental comfort design and discusses the socio-cultural aspects of comfort and the sensory communication aspects of environmental comfort design considerations for future control room interiors
Solving complex maintenance planning optimization problems using stochastic simulation and multi-criteria fuzzy decision making
No full textOne of the most important factors in the operations of many cooperations today is to maximize profit and one important tool to that effect is the optimization of maintenance activities. Maintenance activities is at the largest level divided into two major areas, corrective maintenance (CM) and preventive maintenance (PM). When optimizing maintenance activities, by a maintenance plan or policy, we seek to find the best activities to perform at each point in time, be it PM or CM. We explore the use of stochastic simulation, genetic algorithms and other tools for solving complex maintenance planning optimization problems in terms of a suggested framework model based on discrete event simulation
Optimal General Offset Assignment
No full textWe present an exact approach to the General Offset Assignment problem arising in the domain of address code generation for application specific and digital signal processors. General Offset Assignment is composed of two subproblems, namely to find a permutation of variables in memory and to select a responsible address register for each access to one of these variables. Our method is a combination of established techniques to solve both subproblems using integer linear programming. To the best of our knowledge, it is the first approach capable of solving almost all instances of the established OffsetStone benchmark set to global optimality within reasonable time. We provide a first comprehensive evaluation of the quality of several state-of-the-art heuristics relative to the optimal solutions
Low-Power Listening Goes Multi-Channel
No full textExploiting multiple radio channels for communication has been long known as a practical way to mitigate interference in wireless settings.
In Wireless Sensor Networks, however, multi-channel solutions have not reached their full potential:
the MAC layers included in TinyOS or the Contiki OS for example are mostly single-channel.
The literature offers a number of interesting solutions, but experimental results were often too few to build confidence.
We propose a practical extension of low-power listening, MiCMAC, that performs channel hopping, operates in a distributed way, and is independent of upper layers of the protocol stack.
The above properties make it easy to deploy in a variety of scenarios, without any extra configuration/scheduling/channel selection hassle.
We implement our solution in Contiki and evaluate it in a 97-node testbed while running a complete, out-of-the-box low-power IPv6 communication stack (UDP/RPL/6LoWPAN).
Our experimental results demonstrate increased resilience to emulated WiFi interference (e.g., data yield kept above 90% when ContikiMAC drops in the 40% range).
In noiseless environments, MiCMAC keeps the overhead low in comparison to ContikiMAC, achieving performance as high as 99% data yield along with sub-percent duty cycle and sub-second latency for a 1-minute inter-packet interval data collection
Time-Optimal Convergecast with Separated Packet Copying: Scheduling Policies and Performance
No full text"One of Our Hosts in Another Country": Challenges of Data Geolocation in Cloud Storage
No full textPhysical location of data in cloud storage is an increasingly urgent problem. In a short time, it has evolved from the concern of a few regulated businesses to an important consideration for many cloud storage users. One of the characteristics of cloud storage is fluid transfer of data both within and among the data centres of a cloud provider. However, this has weakened the guarantees with respect to control over data replicas, protection of data in transit and physical location of data. This paper addresses the lack of reliable solutions for data placement control in cloud storage systems. We analyse the currently available solutions and identify their shortcomings. Furthermore, we describe a high-level architecture for a trusted, geolocation-based mechanism for data placement control in distributed cloud storage systems, which are the basis of an on-going work to define the detailed protocol and a prototype of such a solution. This mechanism aims to provide granular control over the capabilities of tenants to access data placed on geographically dispersed storage units comprising the cloud storage