3,041 research outputs found
The Second NASA Formal Methods Workshop 1992
The primary goal of the workshop was to bring together formal methods researchers and aerospace industry engineers to investigate new opportunities for applying formal methods to aerospace problems. The first part of the workshop was tutorial in nature. The second part of the workshop explored the potential of formal methods to address current aerospace design and verification problems. The third part of the workshop involved on-line demonstrations of state-of-the-art formal verification tools. Also, a detailed survey was filled in by the attendees; the results of the survey are compiled
A Verified Information-Flow Architecture
SAFE is a clean-slate design for a highly secure computer system, with
pervasive mechanisms for tracking and limiting information flows. At the lowest
level, the SAFE hardware supports fine-grained programmable tags, with
efficient and flexible propagation and combination of tags as instructions are
executed. The operating system virtualizes these generic facilities to present
an information-flow abstract machine that allows user programs to label
sensitive data with rich confidentiality policies. We present a formal,
machine-checked model of the key hardware and software mechanisms used to
dynamically control information flow in SAFE and an end-to-end proof of
noninterference for this model.
We use a refinement proof methodology to propagate the noninterference
property of the abstract machine down to the concrete machine level. We use an
intermediate layer in the refinement chain that factors out the details of the
information-flow control policy and devise a code generator for compiling such
information-flow policies into low-level monitor code. Finally, we verify the
correctness of this generator using a dedicated Hoare logic that abstracts from
low-level machine instructions into a reusable set of verified structured code
generators
Towards the Model-Driven Engineering of Secure yet Safe Embedded Systems
We introduce SysML-Sec, a SysML-based Model-Driven Engineering environment
aimed at fostering the collaboration between system designers and security
experts at all methodological stages of the development of an embedded system.
A central issue in the design of an embedded system is the definition of the
hardware/software partitioning of the architecture of the system, which should
take place as early as possible. SysML-Sec aims to extend the relevance of this
analysis through the integration of security requirements and threats. In
particular, we propose an agile methodology whose aim is to assess early on the
impact of the security requirements and of the security mechanisms designed to
satisfy them over the safety of the system. Security concerns are captured in a
component-centric manner through existing SysML diagrams with only minimal
extensions. After the requirements captured are derived into security and
cryptographic mechanisms, security properties can be formally verified over
this design. To perform the latter, model transformation techniques are
implemented in the SysML-Sec toolchain in order to derive a ProVerif
specification from the SysML models. An automotive firmware flashing procedure
serves as a guiding example throughout our presentation.Comment: In Proceedings GraMSec 2014, arXiv:1404.163
Using Quantitative Methods as Support for Audit of the Distributed Informatics Systems
This paper highlights some issues regarding how an indicators system must be developed and used in an audit process. Distributed systems are presented from de points of view of their main properties, architectures, applications, software quality characteristics and the scope of audit process in such systems. The audit process is defined in accordance to standard ISO 19011 and the main characteristics of this process are highlighted. Before using quantitative methods in audit processes, the framework in which the indicators are built must be defined. There are presented types of indicators used in audit process and classes of measurement scale. An audit process is carried out on different levels and support indicators must be in accordance to audit object. The paper presents some requirements of the indicators depending on the level of audit.Quantitative Methods, Audit Process, Distributed Informatics System
Towards adaptive multi-robot systems: self-organization and self-adaptation
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugÀnglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The development of complex systems ensembles that operate in uncertain environments is a major challenge. The reason for this is that system designers are not able to fully specify the system during specification and development and before it is being deployed. Natural swarm systems enjoy similar characteristics, yet, being self-adaptive and being able to self-organize, these systems show beneficial emergent behaviour. Similar concepts can be extremely helpful for artificial systems, especially when it comes to multi-robot scenarios, which require such solution in order to be applicable to highly uncertain real world application. In this article, we present a comprehensive overview over state-of-the-art solutions in emergent systems, self-organization, self-adaptation, and robotics. We discuss these approaches in the light of a framework for multi-robot systems and identify similarities, differences missing links and open gaps that have to be addressed in order to make this framework possible
A Design Strategy for Deadlock-Free Concurrent Systems
When building concurrent systems, it would be useful to have a collection of reusable processes
to perform standard tasks. However, without knowing certain details of the inner workings of
these components, one can never be sure that they will not cause deadlock when connected to
some particular network.
Here we describe a hierarchical method for designing complex networks of communicating
processeswhich are deadlock-free.We use this to define a safe and simple method for specifying
the communication interface to third party software components. This work is presented using
the CSP model of concurrency and the occam2.1 programming language
Requirements traceability in model-driven development: Applying model and transformation conformance
The variety of design artifacts (models) produced in a model-driven design process results in an intricate relationship between requirements and the various models. This paper proposes a methodological framework that simplifies management of this relationship, which helps in assessing the quality of models, realizations and transformation specifications. Our framework is a basis for understanding requirements traceability in model-driven development, as well as for the design of tools that support requirements traceability in model-driven development processes. We propose a notion of conformance between application models which reduces the effort needed for assessment activities. We discuss how this notion of conformance can be integrated with model transformations
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