Resources In Cyber-physical Systems Research Articles

Semantic-based discovery method for high-performance computing resources in cyber-physical systems

High-performance computing (HPC) systems with powerful computing capabilities are becoming increasingly significant in the large-scale cyber-physical systems (CPS), helping CPS process a huge number of real-time data. Nowadays, the efficiency of HPC resource management and discovery becomes a challenging problem in CPS, due to the complex characteristics of HPC resources and the growing demands of the users. Although lots of recent efforts have been conducted to the resource discovery in distributed systems, they cannot be well adapted for the cross-regional HPC environments, due to the lack of unified model for the resources description and consideration for the usability demands of non-expert users. In this paper, we propose novel techniques to try to solve the problem. Specifically, we first propose a unified semantic model named HPCRO for specifying cross-regional HPC resources, and apply ontology reasoning to obtain more semantic information for queries. Moreover, we propose a WordNet-based quick resource index list data structure called WQRIL to improve the query. Finally, according to the proposed model and data structure, we propose an efficient discovery method called ROLD for cross-regional HPC resources. Extensive experimental results demonstrate that, our proposals not only maintain efficient resource discovery performance, but also achieve the highest precision rate (94.76%), recall rate (92.34%) and F1-score (93.53%).

A constraint and risk-aware approach to attribute-based access control for cyber-physical systems

Cyber-physical systems (CPSs) integrate cyber components and physical processes. This integration enhances the capabilities of physical systems by incorporating intelligence into objects and services. On the other hand, the integration of cyber and physical components and the interaction between them introduce new security threats. Since CPSs are mostly safety-critical systems, data stored and communicated in them are highly critical. Hence, there is a crucial need for protecting the data and resources in CPSs against unauthorized accesses. In this paper, we propose an access control (AC) framework to address CPS related security issues. The proposed framework consists of two parts: a Cyber-Physical Access Control model (CPAC) and a Generalized Action Generation Model (GAGM). CPAC utilizes an attribute-based approach and extends it with cyber-physical components and cyber-physical interactions. In addition, we incorporate Separation of Duty (SoD) constraints into the CPAC model. GAGM is used to augment the enforcement of access policies. We present formal representations of CPAC and GAGM and demonstrate their use in a sample scenario for a medical CPS. We propose an algorithm for enforcing authorization policies. We implement the CPAC model and compare its performance against the core attribute-based access control model. We present an authorization enforcement approach and show through our experimental results its feasibility.

Correcting design flaws: An improved and cloud assisted key agreement scheme in cyber physical systems

The on demand availability of resources in Cyber physical system (CPS) has emerged as a viable service providing platform to improve the resource usability and reducing the infrastructure costs. Nevertheless, the development recompenses can only be realized after avoiding security and privacy issues. A secure and reliable CPS can offer improved efficiency, usability and reliability along with autonomy. To secure such systems, in 2018 Challa et al. (2018) proposed a security system to extend an authenticated key agreement between a user and a cloud server via trusted authority; as an application, they also customized their system to work with autonomous smart meter and cloud server. Challa et al. then claimed the security of their proposed scheme through formal, informal and automated validations. However, this paper unveils the weaknesses of their scheme and shows that their scheme cannot facilitate in forming a session key between the user/smart meter and the cloud server. Precisely, in the presence of more than one registered users/smart meters, the latter in their scheme may never receive a response message because of a critical design error. Moreover, their scheme lacks the untraceable anonymity and the lack of request verification on cloud server side may also lead to replay and/or denial of services attack. The article then introduces an improved and secure authentication system free of correctness issues, to facilitate a key agreement between user and cloud server via trusted authority. As an application, the proposed system also works for smart meter and cloud server to reach a key agreement. Based on the hardness assumption of Elliptic Curve Decisional Diffi-Hellman Problem (ECDDHP), the formal Random oracle model proves the security of the proposed scheme. Moreover, the robustness of the scheme is explained through informal analysis. The proposed system while providing all known security features has slightly increased the computation and communication costs as compared with the scheme of Challa et al. The proposed scheme completes a cycle of authentication by exchanging 2080 bits in just 13.4066 ms.

Guest editorial for special issue on cyber-physical systems

CYBER-PHYSICAL system is a system of collaborating computational elements to control physical entities. The coordination and the tight link between computational, virtual and physical resources in cyber-physical system will have a pervasive effect on our everyday life. The development of cyber-physical system will create new opportunities for the introduction of services that will enhance the quality of life of the society as a whole. Research advances in cyber-physical systems promise to transform our world with systems that will far exceed those of today in terms of: effectiveness, adaptability, autonomicity, energy efficiency, precision, reliability, safety, usability, scalability, stability and user-centric applicability. Moreover, recently the sensor web concept came into foreground, aiming at combining distributed sensing with the ubiquitous connectivity and accessibility of the web, therefore facilitating the close interaction of digital world with physical world. The technical challenges of cyber-physical systems are significant, and of high research and practical importance, mainly stemming from the fact that traditionally different groups of scientists deal with this setting without much interaction, using disjoint sets of techniques. Towards merging the cyber and physical world, well-defined analytical models, methodologies and experimental validations are required in order to build systems capable of orchestrating heterogeneous components together in a flexible and efficient way. The control systems community has been consistently engaged in the development of theories, tools, and practices for the analysis and the design of cyber-physical systems. The aim of this special issue is to provide a window into the recent developments of the fundamentals and applications of control of cyber-physical systems.

A framework for automated construction of resource space based on background knowledge

Resource Space Model is a kind of data model which can effectively and flexibly manage the digital resources in cyber-physical system from multidimensional and hierarchical perspectives. This paper...

A framework for automated construction of resource space based on background knowledge

Resource Space Model is a kind of data model which can effectively and flexibly manage the digital resources in cyber-physical system from multidimensional and hierarchical perspectives. This paper focuses on constructing resource space automatically. We propose a framework that organizes a set of digital resources according to different semantic dimensions combining human background knowledge in WordNet and Wikipedia. The construction process includes four steps: extracting candidate keywords, building semantic graphs, detecting semantic communities and generating resource space. An unsupervised statistical language topic model (i.e., Latent Dirichlet Allocation) is applied to extract candidate keywords of the facets. To better interpret meanings of the facets found by LDA, we map the keywords to Wikipedia concepts, calculate word relatedness using WordNet’s noun synsets and construct corresponding semantic graphs. Moreover, semantic communities are identified by GN algorithm. After extracting candidate axes based on Wikipedia concept hierarchy, the final axes of resource space are sorted and picked out through three different ranking strategies. The experimental results demonstrate that the proposed framework can organize resources automatically and effectively.