scholarly journals Continuous Contract Based Verification of Updates in Maritime Shipboard Equipment

2021 ◽  
Vol 9 (7) ◽  
pp. 688
Author(s):  
Georg Hake ◽  
Carl Philipp Hohl ◽  
Axel Hahn
Keyword(s):  
Impact Analysis ◽  
Software Systems ◽  
Test Procedures ◽  
System Failures ◽  
Safety Critical ◽  
Novel Approach ◽  
System Composition ◽  
Software Lifecycle ◽  
Update Process ◽  
Configuration Changes

Modern control systems in the maritime domain are increasingly controlled by software systems and become subject to updates and configuration changes during operation. Moreover, with the shift to autonomous vessels and cars, these software-based systems are taking on more and more safety-critical tasks, so the risks associated with system failures are increasing. Unlike before, it becomes necessary to verify the continuously adapting modules of a vehicle not only before deployment, but to establish continuous verification capabilities during all phases of the product lifecycle, from the design to the system in operation. Hence, in case of an update, deviations from the expected behavior can be automatically detected and relevant measures can be initiated. In this work, a contract-based verification framework is presented that includes automatable and formally analyzable behavioral descriptors in form of assumption-guarantee contracts for all phases of the software lifecycle to provide static and dynamic verification capabilities alongside a dynamically changing system composition. By utilizing contractually defined behavior descriptions, classic test procedures, such as simulations, are supplemented by a formally testable level that is applied to all phases of the update process. A conceptual-deductive methodology was chosen, building on the identified requirements to develop an overarching update framework that adds contractual descriptions to the traditional development case. Based on the presented framework, the verifiable modification of a safety-critical software system is demonstrated. The approach is evaluated using a maritime collision-avoidance system and the verification steps are evaluated along the update process. The framework offers a novel approach to complement existing test procedures by enabling formal impact analysis and incremental verification of updates.

scholarly journals Standalone Behaviour-Based Attack Detection Techniques for Distributed Software Systems via Blockchain

2021 ◽  
Vol 11 (12) ◽  
pp. 5685
Author(s):  
Hosam Aljihani ◽  
Fathy Eassa ◽  
Khalid Almarhabi ◽  
Abdullah Algarni ◽  
Abdulaziz Attaallah
Keyword(s):  
Attack Detection ◽  
Detection Methods ◽  
Software Systems ◽  
Distributed Software ◽  
Detection Techniques ◽  
Detection Systems ◽  
Novel Approach ◽  
Validation Experiment ◽  
Critical Issues ◽  
Concrete Solution

With the rapid increase of cyberattacks that presently affect distributed software systems, cyberattacks and their consequences have become critical issues and have attracted the interest of research communities and companies to address them. Therefore, developing and improving attack detection techniques are prominent methods to defend against cyberattacks. One of the promising attack detection methods is behaviour-based attack detection methods. Practically, attack detection techniques are widely applied in distributed software systems that utilise network environments. However, there are some other challenges facing attack detection techniques, such as the immutability and reliability of the detection systems. These challenges can be overcome with promising technologies such as blockchain. Blockchain offers a concrete solution for ensuring data integrity against unauthorised modification. Hence, it improves the immutability for detection systems’ data and thus the reliability for the target systems. In this paper, we propose a design for standalone behaviour-based attack detection techniques that utilise blockchain’s functionalities to overcome the above-mentioned challenges. Additionally, we provide a validation experiment to prove our proposal in term of achieving its objectives. We argue that our proposal introduces a novel approach to develop and improve behaviour-based attack detection techniques to become more reliable for distributed software systems.

A NOVEL APPROACH TO VERIFY GRAPH SCHEMA-BASED SOFTWARE SYSTEMS

2009 ◽  
Vol 19 (06) ◽  
pp. 857-870 ◽  
Author(s):  
VAHID RAFE ◽  
ADEL T. RAHMANI
Keyword(s):  
Graph Transformation ◽  
Behavioral Modeling ◽  
Model Transformations ◽  
Software Systems ◽  
Hierarchical Systems ◽  
Input Language ◽  
Novel Approach ◽  
Graph Schema ◽  
Transformation Systems ◽  
Graph Transformation Systems

Graph Grammars have recently become more and more popular as a general formal modeling language. Behavioral modeling of dynamic systems and model to model transformations are a few well-known examples in which graphs have proven their usefulness in software engineering. A special type of graph transformation systems is layered graphs. Layered graphs are a suitable formalism for modeling hierarchical systems. However, most of the research so far concentrated on graph transformation systems as a modeling means, without considering the need for suitable analysis tools. In this paper we concentrate on how to analyze these models. We will describe our approach to show how one can verify the designed graph transformation systems. To verify graph transformation systems we use a novel approach: using Bogor model checker to verify graph transformation systems. The AGG-like graph transformation systems are translated to BIR — the input language of Bogor — and Bogor verifies that model against some properties defined by combining LTL and special purpose graph rules. Supporting schema-based and layered graphs characterize our approach among existing solutions for verification of graph transformation systems.

How Do I Assess Our Cyber Risk?

2021 ◽  
pp. 41-57
Author(s):  
Gregory Falco ◽  
Eric Rosenbach
Keyword(s):  
Communication Networks ◽  
Impact Analysis ◽  
Critical Systems ◽  
Safety Critical ◽  
Safety Critical Systems ◽  
Mission Critical ◽  
Delivery Networks ◽  
Cyber Risk ◽  
Digital Assets

The question “How do I assess our cyber risk?” addresses how to identify and characterize cyber risk unique to an organization’s critical systems, networks, and data. The chapter begins with a case study about a cyberattack on Ukraine’s electric grid. It details risk assessment for three types of critical systems: mission-critical systems, business-critical systems, and safety-critical systems. It explains the three types of networks critical to many organizations: business and administrative networks, operational and service delivery networks, and communication networks. In outlining the “CIA triad,” it shows how cyber risk can be characterized as a confidentiality, integrity, or availability issue relating to digital assets. Further, it describes how to assess the importance of different digital assets and how to prioritize them using a business impact analysis (BIA). The chapter concludes with real-world Embedded Endurance strategy lessons Rosenbach gained in Saudi Arabia in the wake of one of the world’s most destructive cyberattacks.

Formal Approaches to Systems Analysis Using UML

2002 ◽  
pp. 324-341
Author(s):  
Jonathan Whittle
Keyword(s):  
Formal Methods ◽  
Development Strategy ◽  
Ad Hoc ◽  
Formal Analysis ◽  
Daily Basis ◽  
Software Systems ◽  
Industry Standard ◽  
Mathematical Techniques ◽  
Software Lifecycle ◽  
Modeling Level

Formal methods, whereby a system is described and/or analyzed using precise mathematical techniques, is a well-established and yet, under-used approach for developing software systems. One of the reasons for this is that project deadlines often impose an unsatisfactory development strategy in which code is produced on an ad hoc basis without proper thought about the requirements and design of the piece of software in mind. The result is a large, often poorly documented and un-modular monolith of code that does not lend itself to formal analysis. Because of their complexity, formal methods work best when code is well structured, e.g., when they are applied at the modeling level. UML is a modeling language that is easily learned by system developers and, more importantly, an industry standard, which supports communication between the various project stakeholders. The increased popularity of UML provides a real opportunity for formal methods to be used on a daily basis within the software lifecycle. Unfortunately, the lack of precision of UML means that many formal techniques cannot be applied directly. If formal methods are to be given the place they deserve within UML, a more precise description of UML must be developed. This chapter surveys recent attempts to provide such a description, as well as techniques for analyzing UML models formally.

Automated Tool-Orientation Determinations for 4-Axis Non-Gouge, Non-Interference Milling of Axial-Flow Compressors Airfoils

2007 ◽  
Author(s):  
Zezhong C. Chen ◽  
Gang Liu
Keyword(s):  
Manufacturing Industry ◽  
Axial Flow ◽  
Optimization Method ◽  
Free Form ◽  
Software Systems ◽  
Cnc Milling ◽  
Novel Approach ◽  
Cad Cam ◽  
Free Form Surfaces ◽  
Axial Flow Compressors

As important components of gas turbine engines, axial-flow compressors have been improved with a more complex and accurate airfoil design to meet high aerodynamic requirements; specifically, the pressure and suction surfaces of the airfoils (or blades) are now represented with free-form surfaces in CAD software systems. Since quality of the blades affects efficiency of the engines and safety of the aircrafts, some types of compressors are produced with the blades and the hub as a single piece on 4-axis CNC milling machines. However, it is still quite challenging to automatically determine cutter sizes and orientations without gouging and interference during the 4-axis milling, because the geometric shape of the blades is complex and the blades overlap with each other. As a result, the established method of determining tool size and orientation in industry is by trial and error in a repetitive process of selecting cutters and planning tool-paths with CAM systems. To address this problem, a novel approach is proposed to automatically determine cutter sizes and orientations for 4-axis milling of the axial-flow compressors blades without gouging and interference. The main contribution of this work is that (1) a mathematical model for optimizing cutter sizes in 4-axis milling is established; and (2) by applying a global optimization method — the particle swarm optimization method — to this model, the maximum allowable size of a cutter and its corresponding orientation can be found at each cutter-contact (CC) point on the surface being machined. Therefore, all the maximum allowable sizes of cutters for all the CC points and the corresponding cutter orientations can be computed. A group of standard cutters are then selected; each of which can sweep particular CC points without damaging the compressor. Since it is efficient and reliable, this newly proposed approach can be directly implemented in commercial CAD/CAM software systems to benefit the manufacturing industry.

Sign in / Sign up

Export Citation Format

Share Document