Ilsun You

Malware Obfuscation Techniques: A Brief Survey

As the obfuscation is widely used by malware writers to evade antivirus scanners, so it becomes important to analyze how this technique is applied to malwares. This paper explores the malware obfuscation techniques while reviewing the encrypted, oligomorphic, polymorphic and metamorphic malwares which are able to avoid detection. Moreover, we discuss the future trends on the malware obfuscation techniques.

Comparative Handover Performance Analysis of IPv6 Mobility Management Protocols

IPv6 mobility management is one of the most challenging research topics for enabling mobility service in the forthcoming mobile wireless ecosystems. The Internet Engineering Task Force has been working for developing efficient IPv6 mobility management protocols. As a result, Mobile IPv6 and its extensions such as Fast Mobile IPv6 and Hierarchical Mobile IPv6 have been developed as host-based mobility management protocols. While the host-based mobility management protocols were being enhanced, the network-based mobility management protocols such as Proxy Mobile IPv6 (PMIPv6) and Fast Proxy Mobile IPv6 (FPMIPv6) have been standardized. In this paper, we analyze and compare existing IPv6 mobility management protocols including the recently standardized PMIPv6 and FPMIPv6. We identify each IPv6 mobility management protocols characteristics and performance indicators by examining handover operations. Then, we analyze the performance of the IPv6 mobility management protocols in terms of handover latency, handover blocking probability, and packet loss. Through the conducted numerical results, we summarize considerations for handover performance.

Ensuring attribute privacy protection and fast decryption for outsourced data security in mobile cloud computing

Abstract Although many users outsource their various data to clouds, data security and privacy concerns are still the biggest obstacles that hamper the widespread adoption of cloud computing. Anonymous attribute-based encryption (anonymous ABE) enables fine-grained access control over cloud storage and preserves receivers’ attribute privacy by hiding attribute information in ciphertexts. However, in existing anonymous ABE work, a user knows whether attributes and a hidden policy match or not only after repeating decryption attempts. And, each decryption usually requires many pairings and the computation overhead grows with the complexity of the access formula. Hence, existing schemes suffer a severe efficiency drawback and are not suitable for mobile cloud computing where users may be resource-constrained. In this paper, we propose a novel technique called match-then-decrypt , in which a matching phase is additionally introduced before the decryption phase . This technique works by computing special components in ciphertexts, which are used to perform the test that if the attribute private key matches the hidden access policy in ciphertexts without decryption. For the sake of fast decryption, special attribute secret key components are generated which allow aggregation of pairings during decryption. We propose a basic anonymous ABE construction, and then obtain a security-enhanced extension based on strongly existentially unforgeable one-time signatures. In the proposed constructions, the computation cost of an attribute matching test is less than one decryption operation, which only needs small and constant number of pairings. Formal security analysis and performance comparisons indicate that the proposed solutions simultaneously ensure attribute privacy and improve decryption efficiency for outsourced data storage in mobile cloud computing.

A cross-layer protocol of spectrum mobility and handover in cognitive LTE networks

Abstract Cognitive radio technique is the next step toward efficient wireless bandwidth utilization. While some of the spectrum bands (unlicensed band) have been increasingly used, most of the other spectrum resources (licensed band) are underutilized. This drives the challenges of open spectrum and dynamic spectrum access concepts, which allows unlicensed users (or called secondary users, SUs) equipped with cognitive radios to opportunistically access the spectrum not used by licensed users (or called primary users, PUs). Most existing results mainly focus on designing the lower-layer cognitive radio problems. In the literature, this is the first result to investigate the higher-layer solution for cognitive radio networks. In this paper, we present a cross-layer protocol of spectrum mobility (layer-2) and handover (layer-3) in cognitive LTE networks. With the consideration of the Poisson distribution model of spectrum resources, a cross-layer handoff protocol with the minimum expected transmission time is developed in cognitive LTE networks. Performance analysis of the proposed handoff protocol is investigated. Finally, simulation results illustrates the proposed handoff protocol significantly reduces the expected transmission time and the spectrum mobility ratio.

New order preserving encryption model for outsourced databases in cloud environments

The order of the plaintext remains in the ciphertext, so order-preserving encryption (OPE) scheme is under threat if the adversary is allowed to query for many times. To hide the order in the ciphertext, the only ideal-security OPE scheme (Popa et al., 2013) requires the database server to maintain extra information and realize comparison or range query by user defined functions (UDFs). However, order operations will no longer be performed directly on the ciphertext. It will affect the efficiency and make this scheme to be not suitable for some cases.In this paper, we aim at constructing efficient and programmable OPE scheme for outsourced databases. Firstly, we introduce the system model of outsourced database where OPE scheme will be used, show that ciphertext-only attack is basic and practical security goal. Secondly, we discuss the statistical attack for OPE schemes, point out how to hide data distribution and data frequency is important when designing OPE schemes. Thirdly, we propose a new simple OPE model, which uses message space expansion and nonlinear space split to hide data distribution and frequency and further analyze its security against two kinds of attack in details. Finally, we discuss implementation details including how to use our OPE scheme in the database applications. And we also evaluate its performance through the experiment. The security analysis and performance evaluation show that our OPE scheme is secure enough and more efficient.

A chain-cluster based routing algorithm for wireless sensor networks

Wireless sensor networks (WSNs) are an emerging technology for monitoring physical world. Different from the traditional wireless networks and ad hoc networks, the energy constraint of WSNs makes energy saving become the most important goal of various routing algorithms. For this purpose, a cluster based routing algorithm LEACH (low energy adaptive clustering hierarchy) has been proposed to organize a sensor network into a set of clusters so that the energy consumption can be evenly distributed among all the sensor nodes. Periodical cluster head voting in LEACH, however, consumes non-negligible energy and other resources. While another chain-based algorithm PEGASIS (power- efficient gathering in sensor information systems) can reduce such energy consumption, it causes a longer delay for data transmission. In this paper, we propose a routing algorithm called CCM (Chain-Cluster based Mixed routing), which makes full use of the advantages of LEACH and PEGASIS, and provide improved performance. It divides a WSN into a few chains and runs in two stages. In the first stage, sensor nodes in each chain transmit data to their own chain head node in parallel, using an improved chain routing protocol. In the second stage, all chain head nodes group as a cluster in a self- organized manner, where they transmit fused data to a voted cluster head using the cluster based routing. Experimental results demonstrate that our CCM algorithm outperforms both LEACH and PEGASIS in terms of the product of consumed energy and delay, weighting the overall performance of both energy consumption and transmission delay.

Multidisciplinary Research and Practice for Information Systems

Researchers often have to understand new knowledge areas, and identify research gaps and immature areas in them. They have to understand and link numerous publications to achieve this goal. This is difficult, because natural language has to be analyzed in the publications, and implicit relations between them have to be discovered. We propose to utilize the structuring possibilities of ontologies to make the relations between publications, knowledge objects (e.g., methods, tools, notations), and knowledge areas explicit. Furthermore, we use Kitchenham’s work on structured literature reviews and apply it to the ontology. We formalize relations between objects in the ontology using Codd’s relational algebra to support different kinds of literature research. These formal expressions are implemented as ontology queries. Thus, we implement an immature research area analysis and research gap identification mechanism. The ontology and its relations are implemented based on the Semantic MediaWiki+ platform.

An Optimization-Based Scheme for Efficient Virtual Machine Placement

According to the important methodology of convex optimization theory, the energy-efficient and scalability problems of modern data centers are studied. Then a novel virtual machine (VM) placement scheme is proposed for solving these problems in large scale. Firstly, by referring the definition of VM placement fairness and utility function, the basic algorithm of VM placement which fulfills server constraints of physical machines is discussed. Then, we abstract the VM placement as an optimization problem which considers the inherent dependencies and traffic between VMs. By given the structural differences of recently proposed data center architectures, we further investigate a comparative analysis on the impact of the network architectures, server constraints and application dependencies on the potential performance gain of optimization-based VM placement. Comparing with the existing schemes, the performance improvements are illustrated from multiple perspectives, such as reducing the number of physical machines deployment, decreasing communication cost between VMs, improving energy-efficient and scalability of data centers.

Design and Implementation of a Ubiquitous ECG Monitoring System Using SIP and the Zigbee Network

The use of a Zigbee network in various health monitoring systems has become well accepted. This network promises to develop health care by allowing prompt, secure, low power, and low-cost health monitoring with real-time medical data transmission and update via the session initiation protocol (SIP). In this paper, we present a description and system architecture for a ubiquitous ECG monitoring system based on SIP and the Zigbee Network. Our proposed ubiquitous ECG monitoring system includes a wireless ECG sensor, ECG console, a Zigbee module, a SIP registrar and proxy server, a database server, and wireless devices for users. This system specifically targets patients, senior citizens, and others who may benefit from continuous, Remote health monitoring systems. We performed an evaluation of the results of this research through an ECG monitoring system design and experimentation with a pervasive computing test bed.

Availability, Reliability and Security for Business, Enterprise and Health Information Systems

This book constitutes the refereed proceedings of the IFIP WG 8.4/8.9 International Cross Domain Conference and Workshop on Availability, Reliability and Security - Multidisciplinary Research and Practice for Business, Enterprise and Health Information Systems, ARGES 2011, held in Vienna, Austria, in August 2011. The 29 revised papers presented were carefully reviewed and selected for inclusion in the volume. The papers concentrate on the many aspects of availability, reliability and security for information systems as a discipline bridging the application fields and the well-defined computer science field. They are organized in three sections: multidisciplinary research and practice for business, enterprise and health information systems; massive information sharing and integration and electronic healthcare; and papers from the colocated International Workshop on Security and Cognitive Informatics for Homeland Defense.