Young-Sik Jeong

DistBlockNet: A Distributed Blockchains-Based Secure SDN Architecture for IoT Networks

The rapid increase in the number and diversity of smart devices connected to the Internet has raised the issues of flexibility, efficiency, availability, security, and scalability within the current IoT network. These issues are caused by key mechanisms being distributed to the IoT network on a large scale, which is why a distributed secure SDN architecture for IoT using the blockchain technique (DistBlockNet) is proposed in this research. It follows the principles required for designing a secure, scalable, and efficient network architecture. The DistBlockNet model of IoT architecture combines the advantages of two emerging technologies: SDN and blockchains technology. In a verifiable manner, blockchains allow us to have a distributed peer-to-peer network where non-confident members can interact with each other without a trusted intermediary. A new scheme for updating a flow rule table using a blockchains technique is proposed to securely verify a version of the flow rule table, validate the flow rule table, and download the latest flow rules table for the IoT forwarding devices. In our proposed architecture, security must automatically adapt to the threat landscape, without administrator needs to review and apply thousands of recommendations and opinions manually. We have evaluated the performance of our proposed model architecture and compared it to the existing model with respect to various metrics. The results of our evaluation show that DistBlockNet is capable of detecting attacks in the IoT network in real time with low performance overheads and satisfying the design principles required for the future IoT network.

Social network security: Issues, challenges, threats, and solutions

Abstract Social networks are very popular in todays world. Millions of people use various forms of social networks as they allow individuals to connect with friends and family, and share private information. However, issues related to maintaining the privacy and security of a users information can occur, especially when the users uploaded content is multimedia, such as photos, videos, and audios. Uploaded multimedia content carries information that can be transmitted virally and almost instantaneously within a social networking site and beyond. In this paper, we present a comprehensive survey of different security and privacy threats that target every user of social networking sites. In addition, we separately focus on various threats that arise due to the sharing of multimedia content within a social networking site. We also discuss current state-of- the-art defense solutions that can protect social network users from these threats. We then present future direction and discuss some easy-to-apply response techniques to achieve the goal of a trustworthy and secure social network ecosystem.

Iceberg Clique queries in large graphs

Abstract This paper investigates the Iceberg Clique (IC) queries in a large graph, specially, given a user-specified threshold θ, an IC query reports the cliques where the number of vertices exceeds ⌊θ|V|⌋. Toward this end, a practical IC query theorem is formally proposed and proved. With this proposed query theorem, a formal context and its corresponding iceberg concept lattice are first constructed from an input graph topology by Modified Adjacency Matrix; then, we prove that the IC queries problem is equivalent to finding the iceberg equiconcepts whose number of elements exceeds ⌊θ|V|⌋. Theoretical analysis and experimental results demonstrate that the proposed query algorithm is feasible and efficient for finding the iceberg cliques from large graphs.

Investigating Apache Hama: a bulk synchronous parallel computing framework

The quantity of digital data is growing exponentially, and the task to efficiently process such massive data is becoming increasingly challenging. Recently, academia and industry have recognized the limitations of the predominate Hadoop framework in several application domains, such as complex algorithmic computation, graph, and streaming data. Unfortunately, this widely known map-shuffle-reduce paradigm has become a bottleneck to address the challenges of big data trends. The demand for research and development of novel massive computing frameworks is increasing rapidly, and systematic illustration, analysis, and highlights of potential research areas are vital and very much in demand by the researchers in the field. Therefore, we explore one of the emerging and promising distributed computing frameworks, Apache Hama. This is a top level project under the Apache Software Foundation and a pure bulk synchronous parallel model for processing massive scientific computations, e.g. graph, matrix, and network algorithms. The objectives of this contribution are twofold. First, we outline the current state of the art, distinguish the challenges, and frame some research directions for researchers and application developers. Second, we present real-world use cases of Apache Hama to illustrate its potential specifically to the industrial community.

Novel assessment method for accessing private data in social network security services

Social network services (SNSs) have become one of the core Internet-based application services in recent years. Through SNSs, diverse kinds of private data are shared with users’ friends and SNS plug-in applications. However, these data can be exposed via abnormal private data access. For example, the addition of fake friends to a user’s account is one approach to gain access to a private user’s data. Private user data can be protected from being accessed by using an automated method to assess information. This paper proposes a method that evaluates private data accesses for social network security. By defining normal private data access patterns in advance, abnormal private data access patterns can be exposed. Normal private data access patterns are generated by analyzing all of the consecutive private data accesses of users based on Bayesian probability. We have proven the effectiveness of our approach by conducting experiments where the private data access signals of Twitter accounts were collected and analyzed.

Data-Filtering System to Avoid Total Data Distortion in IoT Networking

In the Internet of Things (IoT) networking, numerous objects are connected to a network. They sense events and deliver the sensed information to the cloud. A lot of data is generated in the IoT network, and servers in the cloud gather the sensed data from the objects. Then, the servers analyze the collected data and provide proper intelligent services to users through the results of the analysis. When the server analyzes the collected data, if there exists malfunctioning data, distortional results of the analysis will be generated. The distortional results lead to misdirection of the intelligent services, leading to poor user experience. In the analysis for intelligent services in IoT, malfunctioning data should be avoided because integrity of the collected data is crucial. Therefore, this paper proposes a data-filtering system for the server in the cloud. The proposed data-filtering system is placed in front of the server and firstly receives the sensed data from the objects. It employs the naive Bayesian classifier and, by learning, classifies the malfunctioning data from among the collected data. Data with integrity is delivered to the server for analysis. Because the proposed system filters the malfunctioning data, the server can obtain accurate analysis results and reduce computing load. The performance of the proposed data-filtering system is evaluated through computer simulation. Through the simulation results, the efficiency of the proposed data-filtering system is shown.

A Robust Method for Finding the Automated Best Matched Genes Based on Grouping Similar Fragments of Large-Scale References for Genome Assembly

Big data research on genomic sequence analysis has accelerated considerably with the development of next-generation sequencing. Currently, research on genomic sequencing has been conducted using various methods, ranging from the assembly of reads consisting of fragments to the annotation of genetic information using a database that contains known genome information. According to the development, most tools to analyze the new organelles’ genetic information requires different input formats such as FASTA, GeneBank (GB) and tab separated files. The various data formats should be modified to satisfy the requirements of the gene annotation system after genome assembly. In addition, the currently available tools for the analysis of organelles are usually developed only for specific organisms, thus the need for gene prediction tools, which are useful for any organism, has been increased. The proposed method—termed the genome_search_plotter—is designed for the easy analysis of genome information from the related references without any file format modification. Anyone who is interested in intracellular organelles such as the nucleus, chloroplast, and mitochondria can analyze the genetic information using the assembled contig of an unknown genome and a reference model without any modification of the data from the assembled contig.

Adaptive Job Load Balancing Scheme on Mobile Cloud Computing with Collaborative Architecture

The adaptive mobile resource offloading (AMRO) proposed in this paper is a load balancing scheme for processing large-scale jobs using mobile resources without a cloud server. AMRO is applied in a mobile cloud computing environment based on collaborative architecture. A load balancing scheme with efficient job division and optimized job allocation is needed because the resources for mobile devices will not always be provided consistently in this environment. Therefore, a job load balancing scheme is proposed that considers personal usage patterns and the dynamic resource state of the mobile devices. The delay time for computer job processing is minimized through dynamic job reallocation and adaptive job allocation in the disability state that occurs due to unexpected problems and to excessive job allocations by the mobile devices providing the resources for the mobile cloud computing. In order to validate the proposed load balancing scheme, an adaptive mobile resource management without cloud server (AMRM) protocol was designed and implemented, and the improved processing speed was verified in comparison with the existing offloading method. The improved job processing speed in the mobile cloud environment is demonstrated through job allocation based on AMRM and by taking into consideration the idle resources of the mobile devices. Furthermore, the resource waste of the mobile devices is minimized through adaptive offloading and consideration of both insufficient and idle resources.

DIaaS: Resource Management System for the Intra-Cloud with On-Premise Desktops

Infrastructure as a service with desktops (DIaaS) based on the extensible mark-up language (XML) is herein proposed to utilize surplus resources. DIaaS is a traditional surplus-resource integrated management technology. It is designed to provide fast work distribution and computing services based on user service requests as well as storage services through desktop-based distributed computing and storage resource integration. DIaaS includes a nondisruptive resource service and an auto-scalable scheme to enhance the availability and scalability of intra-cloud computing resources. A performance evaluation of the proposed scheme measured the clustering performance time for surplus resource utilization. The results showed improvement in computing and storage services in a connection of at least two computers compared to the traditional method for high-availability measurement of nondisruptive services. Furthermore, an artificial server error environment was used to create a clustering delay for computing and storage services and for nondisruptive services. It was compared to the Hadoop distributed file system (HDFS).

Automatic Generation of Ortho-Photo Texture from Digital Elevation Model

We propose the automatic generation of the ortho-photo data which support realistic scenes for DEM by texture mapping. This ortho-photo data is automatically generated by pattern recognition techniques using Bayesian classifier which uses the features extracted from a DEM and its geo-referenced ortho-photo data as training sets. We defined the various features of each texel such as its height, slope angle, slope direction, surface curvature, hue, saturation and brightness from the training datasets. The proposed method makes possible for mapping texture of a realistic ortho-photo data to virtual terrain data which are unable to take satellite photo or aerial photo. These case are often in of computer game and digital movie area. Also, generating ortho-photo with the enlarged DEM, it does not cause the aliasing from the difference of resolution. It makes very similar images with real photography by shading and efficiently handles ortho-photo data and elevation data occupied enormous storage in cloud computing environment.