Earticle

Runtime verification aims to check whether an application executes its behaviour as specified. Thereby the active execution trace of an application is checked in terms of the actual execution context; diagnosis and, possibly, recovery actions are taken when the specification is violated. In today’s practices, software is increasingly distributed over multiple processes, potentially running at different locations. This is supported by middleware that, to some extent, allows implementing applications in a distribution-transparent way. To enable effective runtime verification in distributed software we focus in this paper on three requirements: (1) distribution-transparent specification of software behaviour, as software is also implemented in such a way, (2) end-to-end verification of behaviour, and (3) automatic generation of verification modules for arbitrary process and distribution structures. We present a novel runtime verification approach satisfying these requirements and present its implementation in the EventChaser system. Furthermore we present an approach that at least minimizes the distribution-awareness of specifications to an acceptable level for software not using supported middleware for inter-process communication.

In hierarchical Peer-to-Peer (P2P) systems, several selected peers are promoted as super-peers to provide an efficient lookup service for the ordinary peers, although this could cause a service bottleneck and a heavy workload at the point of the promoted peers. In this paper, we propose a two-level caching architecture consisting of a level-1 cache and a level-2 cache to relax such bottlenecks in hierarchical P2Ps. Each cache is partitioned into two parts so as to manage both static and dynamic data in a space-efficient manner: static data indicate popular pages which are frequently requested by many users and dynamic data indicate pages which may not be popular but are repeatedly requested during a short time period. The performance of the proposed method is evaluated by simulation. The result indicates that our caching protocol significantly reduces network traffic and exhibits a high hit rate even in small cache sizes.

This paper presents a concurrent error detection (CED) technique for a bit-slice of a full-adder. The proposed method involves computing the sum and carry bits in two alternative ways so that transient faults will be detected by comparing the results (Sum and Carry out) obtained from the two computing paths. This technique attempts to reduce the amount of extra hardware and circuit cost. In order to avoid the problem of extra delay we will propagate the result when the first computation is finished so that dependent computation can commence execution as soon as possible. To prove the efficiency of the proposed method, the circuit is simulated in standard CMOS 32nm technology and some transient faults are voluntarily injected into the circuit layout. The proposed design provides a 12.12% saving in transistor count compared to a DMR (Dual Modular Redundancy) style design.

Highlighting that connectivity and communication are two separate concepts in a Wireless Sensor Network (WSN), we propose a novel model for connectivity of a WSN using firstorder Reed Muller codes. For communication, we choose to work with a model that utilizes Partially Balanced Incomplete Block Designs (PBIBD). Two suitable cryptosystems can now be applied for the two different models. As a result, the resilience of the WSN is appreciably improved without affecting the connectivity and scalability of the original communication model. Secure key establishment has been achieved by converting identifiers (ids) of nodes from public to private or secret information. The node ids which are now known only to individual nodes can be used in pairs to generate new communication keys from the old ones by padding and then applying suitable ‘Hash Functions’. As a result the resilience is further improved.

Compared with hardware-based methods, softwarebased methods which do not need additional hardware costs are regarded as efficient methods for tolerating soft errors. Softwarebased methods which are implemented by software protection imply performance sacrifice. This paper proposes a new configurable approach whose purpose is to balance system reliability and performance to tolerate soft errors via partial software protection. Those unprotected software regions which are motivated by soft error mask on the software level are related to statically dead codes, those codes whose probabilities of being executed are low and some partially dead codes. For those protected codes, we copy all data and operate every operation twice to ensure the data stored in the memory are correct. Additionally, we ensure every branch instruction can jump to the right address by checking the condition and destination address. Finally, our approach is implemented by modification of the compiler. System reliability and performance are evaluated with different configurations. Experimental results demonstrate our aim to balance system reliability and performance.

At present, the “Smart Grid” has emerged as one of the best advanced energy supply chains. This paper looks into the security system of smart grid via the smart planet system. The scope focused on information security criteria that impact on consumer trust and satisfaction. The importance of information security criteria is perceived as the main aspect to impact on customer trust throughout the entire smart grid system. On one hand, this paper also focuses on the selection of the model for developing information security criteria on a smart grid.

We analyse Taiwan’s electricity environment and the Taiwanese AMI architecture, and then design a suitable protocol stack to be used in the AMI system for low voltage users. Based on this proposed protocol stack, we also propose a hierarchical two-layer security scheme to protect the metering data and usage information.

Malware inside networks along with worms and viruses have become a critical concern. Even though several approaches have been proposed to eliminate this severe problem, the vulnerability of the software dissemination server’s platform is often underestimated. Trusted software dissemination based on trusted computing mutual remote attestation mechanisms is a new approach designed to overcome it. But the limited computational capabilities of the TPM device on the sever side is an obvious bottleneck to scalable performance. Without any changes being made to the traditional TPM, and simply by introducing a novel highly efficient remote attestation mechanism specifically tailored for the server platform, we greatly increase the scalability of the server platform. Experimental measurements shows that handling multiple, almost simultaneous, software download requests only increases the average response time by a constant increment, which shows great efficiency when compared to existing linear approaches. Shared key, dealt with by Bilinear-Pairing properties, is also included to protect the attestation session and disseminated software. Implementation details, security analysis and performance evaluation of our system architecture are presented to demonstrate that our approach is feasible for a practical and scalable trusted software dissemination system.

Current technology in trusted computing cannot comply with the requirement of trusted behaviour. One method for trusted computing dynamic attestation is proposed in this paper. This method uses a behaviour model based on the static analysis of binary code. One same source code may have several different binary versions, therefore one method is proposed for building almost the same core function model for different binary versions. This research also overcame the difficulty where some dynamic behaviours could not be obtained by static analysis. The paper also provides solutions for dynamic attestation of some complex programs, such as recursion, library link and multi threads programs.

This paper presents the parallel extended pointaddition and point-double on conic curves over ring Zn firstly. Then the parallel point-multiplication on conic curves over ring Zn is proposed based on the two extended basic operations. The data dependencies of extended point-addition and point-double are deduced by analyzing their definitions. Using the procedure of paralleling extended point-addition as an example, we employ the Chinese Remainder Theorem to divide point-addition over ring Zn into two point-additions over finite field Fp and finite field Fq. After that, the temporary values of point-addition over two finite fields are merged to get the final result of the extended point-addition over ring Zn. An algorithm in our previous work is used directly to parallel the point-multiplication on the basis of the extended point-addition and point-double. The performance evaluation demonstrates that our techniques achieve better efficiency for conic curves cryptosystem over ring Zn than the old parallel algorithms we proposed before.

This paper presents, in the form of a case study, the design, implementation and performance evaluation of Phoenix: a prototype of a fault-tolerant distributed storage web service based on URLs. Our system supports a set of redundancy strategies including simple file-replication, error-coding techniques and a hybrid adaptive technique. The web storage middleware (WSM), which is at the core of the prototype, reuses the URLs of the files to dynamically accommodate data and redundancy load. Experimental assessments show that distributing the users to several web servers compensates for the overhead produced both by generating and distributing data redundancy. We also found that during a non-critical number of web server failures, users do not perceive but a lengthening on the system response times. As expected, peak user requests and network congestion are the most important factors affecting the storage system’s performance.

deviantART is one of the leading social online network sites with a focus on user-generated artworks. The website has a rich data archive of around 150 million images uploaded by its 15 million members, making it the largest art platform today. This paper describes an open source toolkit that provides a humanities scholar with necessary computational tools to analyse and visualise deviantART and similar art collections. To this end, we combine tools from different research fields such as network analysis, computer vision, machine learning and data visualisation. The toolkit provides the functionality to extract data about members and their artworks directly from the deviantART website, using network analysis to select key members for further investigation. The chosen members’ images are automatically downloaded and annotated with different image features, along with which they can be visualised. The visualisation options offered in the implemented toolkit links images to their originals and can be used to explore and analyse the dataset in an interactive way. The toolkit also features an SVM-based classifier to automatically select features to discriminate artists, artworks and styles, which is hidden from the user behind a simple “suggest features” option.