Biblio

Found 19604 results

2019-02-13
Irmak, E., Erkek, İ.  2018.  An overview of cyber-attack vectors on SCADA systems. 2018 6th International Symposium on Digital Forensic and Security (ISDFS). :1–5.

Most of the countries evaluate their energy networks in terms of national security and define as critical infrastructure. Monitoring and controlling of these systems are generally provided by Industrial Control Systems (ICSs) and/or Supervisory Control and Data Acquisition (SCADA) systems. Therefore, this study focuses on the cyber-attack vectors on SCADA systems to research the threats and risks targeting them. For this purpose, TCP/IP based protocols used in SCADA systems have been determined and analyzed at first. Then, the most common cyber-attacks are handled systematically considering hardware-side threats, software-side ones and the threats for communication infrastructures. Finally, some suggestions are given.

2020-01-06
Rezaeighaleh, Hossein, Laurens, Roy, Zou, Cliff C..  2018.  Secure Smart Card Signing with Time-based Digital Signature. 2018 International Conference on Computing, Networking and Communications (ICNC). :182–187.
People use their personal computers, laptops, tablets and smart phones to digitally sign documents in company's websites and other online electronic applications, and one of the main cybersecurity challenges in this process is trusted digital signature. While the majority of systems use password-based authentication to secure electronic signature, some more critical systems use USB token and smart card to prevent identity theft and implement the trusted digital signing process. Even though smart card provides stronger security, any weakness in the terminal itself can compromise the security of smart card. In this paper, we investigate current smart card digital signature, and illustrate well-known basic vulnerabilities of smart card terminal with the real implementation of two possible attacks including PIN sniffing and message alteration just before signing. As we focus on second attack in this paper, we propose a novel mechanism using time-based digital signing by smart card to defend against message alteration attack. Our prototype implementation and performance analysis illustrate that our proposed mechanism is feasible and provides stronger security. Our method uses popular timestamping protocol packets and does not require any new key distribution and certificate issuance.
2019-08-26
Gupta, D. S., Biswas, G. P., Nandan, R..  2018.  Security weakness of a lattice-based key exchange protocol. 2018 4th International Conference on Recent Advances in Information Technology (RAIT). :1–5.

A key exchange protocol is an important primitive in the field of information and network security and is used to exchange a common secret key among various parties. A number of key exchange protocols exist in the literature and most of them are based on the Diffie-Hellman (DH) problem. But, these DH type protocols cannot resist to the modern computing technologies like quantum computing, grid computing etc. Therefore, a more powerful non-DH type key exchange protocol is required which could resist the quantum and exponential attacks. In the year 2013, Lei and Liao, thus proposed a lattice-based key exchange protocol. Their protocol was related to the NTRU-ENCRYPT and NTRU-SIGN and so, was referred as NTRU-KE. In this paper, we identify that NTRU-KE lacks the authentication mechanism and suffers from the man-in-the-middle (MITM) attack. This attack may lead to the forging the authenticated users and exchanging the wrong key.

2019-10-08
Arslan, B., Ulker, M., Akleylek, S., Sagiroglu, S..  2018.  A Study on the Use of Quantum Computers, Risk Assessment and Security Problems. 2018 6th International Symposium on Digital Forensic and Security (ISDFS). :1–6.

In the computer based solutions of the problems in today's world; if the problem has a high complexity value, different requirements can be addressed such as necessity of simultaneous operation of many computers, the long processing times for the operation of algorithms, and computers with hardware features that can provide high performance. For this reason, it is inevitable to use a computer based on quantum physics in the near future in order to make today's cryptosystems unsafe, search the servers and other information storage centers on internet very quickly, solve optimization problems in the NP-hard category with a very wide solution space and analyze information on large-scale data processing and to process high-resolution image for artificial intelligence applications. In this study, an examination of quantum approaches and quantum computers, which will be widely used in the near future, was carried out and the areas in which such innovation can be used was evaluated. Malicious or non-malicious use of quantum computers with this capacity, the advantages and disadvantages of the high performance which it provides were examined under the head of security, the effect of this recent technology on the existing security systems was investigated.

2019-09-09
C. Wang, Z. Lu.  2018.  Cyber Deception: Overview and the Road Ahead. IEEE Security Privacy. 16:80-85.

Since the concept of deception for cybersecurity was introduced decades ago, several primitive systems, such as honeypots, have been attempted. More recently, research on adaptive cyber defense techniques has gained momentum. The new research interests in this area motivate us to provide a high-level overview of cyber deception. We analyze potential strategies of cyber deception and its unique aspects. We discuss the research challenges of creating effective cyber deception-based techniques and identify future research directions.

2019-01-31
Geethanjali, D, Ying, Tan Li, Melissa, Chua Wan Jun, Balachandran, Vivek.  2018.  AEON: Android Encryption Based Obfuscation. Proceedings of the Eighth ACM Conference on Data and Application Security and Privacy. :146–148.

Android applications are vulnerable to reverse engineering which could result in tampering and repackaging of applications. Even though there are many off the shelf obfuscation tools that hardens Android applications, they are limited to basic obfuscation techniques. Obfuscation techniques that transform the code segments drastically are difficult to implement on Android because of the Android runtime verifier which validates the loaded code. In this paper, we introduce a novel obfuscation technique, Android Encryption based Obfuscation (AEON), which can encrypt code segments and perform runtime decryption during execution. The encrypted code is running outside of the normal Android virtual machine, in an embeddable Java source interpreter and thereby circumventing the scrutiny of Android runtime verifier. Our obfuscation technique works well with Android source code and Dalvik bytecode.

2019-05-01
Pillutla, H., Arjunan, A..  2018.  A Brief Review of Fuzzy Logic and Its Usage Towards Counter-Security Issues. 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET). :1-6.

Nowadays, most of the world's population has become much dependent on computers for banking, healthcare, shopping, and telecommunication. Security has now become a basic norm for computers and its resources since it has become inherently insecure. Security issues like Denial of Service attacks, TCP SYN Flooding attacks, Packet Dropping attacks and Distributed Denial of Service attacks are some of the methods by which unauthorized users make the resource unavailable to authorized users. There are several security mechanisms like Intrusion Detection System, Anomaly detection and Trust model by which we can be able to identify and counter the abuse of computer resources by unauthorized users. This paper presents a survey of several security mechanisms which have been implemented using Fuzzy logic. Fuzzy logic is one of the rapidly developing technologies, which is used in a sophisticated control system. Fuzzy logic deals with the degree of truth rather than the Boolean logic, which carries the values of either true or false. So instead of providing only two values, we will be able to define intermediate values.

2020-10-05
Rungger, Matthias, Zamani, Majid.  2018.  Compositional Construction of Approximate Abstractions of Interconnected Control Systems. IEEE Transactions on Control of Network Systems. 5:116—127.

We consider a compositional construction of approximate abstractions of interconnected control systems. In our framework, an abstraction acts as a substitute in the controller design process and is itself a continuous control system. The abstraction is related to the concrete control system via a so-called simulation function: a Lyapunov-like function, which is used to establish a quantitative bound between the behavior of the approximate abstraction and the concrete system. In the first part of the paper, we provide a small gain type condition that facilitates the compositional construction of an abstraction of an interconnected control system together with a simulation function from the abstractions and simulation functions of the individual subsystems. In the second part of the paper, we restrict our attention to linear control system and characterize simulation functions in terms of controlled invariant, externally stabilizable subspaces. Based on those characterizations, we propose a particular scheme to construct abstractions for linear control systems. We illustrate the compositional construction of an abstraction on an interconnected system consisting of four linear subsystems. We use the abstraction as a substitute to synthesize a controller to enforce a certain linear temporal logic specification.

2018-12-10
Beaton, Brian.  2018.  Crucial Answers About Humanoid Capital. Companion of the 2018 ACM/IEEE International Conference on Human-Robot Interaction. :5–12.

Inside AI research and engineering communities, explainable artificial intelligence (XAI) is one of the most provocative and promising lines of AI research and development today. XAI has the potential to make expressible the context and domain-specific benefits of particular AI applications to a diverse and inclusive array of stakeholders and audiences. In addition, XAI has the potential to make AI benefit claims more deeply evidenced. Outside AI research and engineering communities, one of the most provocative and promising lines of research happening today is the work on "humanoid capital" at the edges of the social, behavioral, and economic sciences. Humanoid capital theorists renovate older discussions of "human capital" as part of trying to make calculable and provable the domain-specific capital value, value-adding potential, or relative worth (i.e., advantages and benefits) of different humanoid models over time. Bringing these two exciting streams of research into direct conversation for the first time is the larger goal of this landmark paper. The primary research contribution of the paper is to detail some of the key requirements for making humanoid robots explainable in capital terms using XAI approaches. In this regard, the paper not only brings two streams of provocative research into much-needed conversation but also advances both streams.

2019-02-08
Ghirardello, K., Maple, C., Ng, D., Kearney, P..  2018.  Cyber Security of Smart Homes: Development of a Reference Architecture for Attack Surface Analysis. Living in the Internet of Things: Cybersecurity of the IoT - 2018. :1-10.

Recent advances in pervasive computing have caused a rapid growth of the Smart Home market, where a number of otherwise mundane pieces of technology are capable of connecting to the Internet and interacting with other similar devices. However, with the lack of a commonly adopted set of guidelines, several IT companies are producing smart devices with their own proprietary standards, leading to highly heterogeneous Smart Home systems in which the interoperability of the present elements is not always implemented in the most straightforward manner. As such, understanding the cyber risk of these cyber-physical systems beyond the individual devices has become an almost intractable problem. This paper tackles this issue by introducing a Smart Home reference architecture which facilitates security analysis. Being composed by three viewpoints, it gives a high-level description of the various functions and components needed in a domestic IoT device and network. Furthermore, this document demonstrates how the architecture can be used to determine the various attack surfaces of a home automation system from which its key vulnerabilities can be determined.

2020-11-02
Ivanov, I, Maple, C, Watson, T, Lee, S.  2018.  Cyber security standards and issues in V2X communications for Internet of Vehicles. Living in the Internet of Things: Cybersecurity of the IoT – 2018. :1—6.

Significant developments have taken place over the past few years in the area of vehicular communication systems in the ITS environment. It is vital that, in these environments, security is considered in design and implementation since compromised vulnerabilities in one vehicle can be propagated to other vehicles, especially given that V2X communication is through an ad-hoc type network. Recently, many standardisation organisations have been working on creating international standards related to vehicular communication security and the so-called Internet of Vehicles (IoV). This paper presents a discussion of current V2X communications cyber security issues and standardisation approaches being considered by standardisation bodies such as the ISO, the ITU, the IEEE, and the ETSI.

2019-02-08
Fang, Yong, Li, Yang, Liu, Liang, Huang, Cheng.  2018.  DeepXSS: Cross Site Scripting Detection Based on Deep Learning. Proceedings of the 2018 International Conference on Computing and Artificial Intelligence. :47-51.

Nowadays, Cross Site Scripting (XSS) is one of the major threats to Web applications. Since it's known to the public, XSS vulnerability has been in the TOP 10 Web application vulnerabilities based on surveys published by the Open Web Applications Security Project (OWASP). How to effectively detect and defend XSS attacks are still one of the most important security issues. In this paper, we present a novel approach to detect XSS attacks based on deep learning (called DeepXSS). First of all, we used word2vec to extract the feature of XSS payloads which captures word order information and map each payload to a feature vector. And then, we trained and tested the detection model using Long Short Term Memory (LSTM) recurrent neural networks. Experimental results show that the proposed XSS detection model based on deep learning achieves a precision rate of 99.5% and a recall rate of 97.9% in real dataset, which means that the novel approach can effectively identify XSS attacks.

2019-01-31
Zhang, H., Chen, L., Liu, Q..  2018.  Digital Forensic Analysis of Instant Messaging Applications on Android Smartphones. 2018 International Conference on Computing, Networking and Communications (ICNC). :647–651.

In this paper, we discuss the digital forensic procedure and techniques for analyzing the local artifacts from four popular Instant Messaging applications in Android. As part of our findings, the user chat messages details and contacts were investigated for each application. By using two smartphones with different brands and the latest Android operating systems as experimental objects, we conducted digital investigations in a forensically sound manner. We summarize our findings regarding the different Instant Messaging chat modes and the corresponding encryption status of artifacts for each of the four applications. Our findings can be helpful to many mobile forensic investigations. Additionally, these findings may present values to Android system developers, Android mobile app developers, mobile security researchers as well as mobile users.

2018-07-13
Yangfend Qu, Illinois Institute of Technology, Xin Liu, Illinois Institute of Technology, Dong Jin, Illinois Institute of Technology, Yuan Hong, Illinois Institute of Technology, Chen Chen, Argonne National Laboratory.  2018.  Enabling a Resilient and Self-healing PMU Infrastructure Using Centralized Network Control. 2018 ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization.

Many of the emerging wide-area monitoring protection and control (WAMPAC) applications in modern electrical grids rely heavily on the availability and integrity of widespread phasor measurement unit (PMU) data. Therefore, it is critical to protect PMU networks against growing cyber-attacks and system faults. In this paper, we present a self-healing PMU network design that considers both power system observability and communication network characteristics. Our design utilizes centralized network control, such as the emerging software-defined networking (SDN) technology, to design resilient network self-healing algorithms against cyber-attacks. Upon detection of a cyber-attack, the PMU network can reconfigure itself to isolate compromised devices and re-route measurement
data with the goal of preserving the power system observability. We have developed a proof-of-concept system in a container-based network testbed using integer linear programming to solve a graphbased PMU system model.We also evaluate the system performance regarding the self-healing plan generation and installation using the IEEE 30-bus system.
 

2020-10-05
Su, Jinsong, Zeng, Jiali, Xiong, Deyi, Liu, Yang, Wang, Mingxuan, Xie, Jun.  2018.  A Hierarchy-to-Sequence Attentional Neural Machine Translation Model. IEEE/ACM Transactions on Audio, Speech, and Language Processing. 26:623—632.

Although sequence-to-sequence attentional neural machine translation (NMT) has achieved great progress recently, it is confronted with two challenges: learning optimal model parameters for long parallel sentences and well exploiting different scopes of contexts. In this paper, partially inspired by the idea of segmenting a long sentence into short clauses, each of which can be easily translated by NMT, we propose a hierarchy-to-sequence attentional NMT model to handle these two challenges. Our encoder takes the segmented clause sequence as input and explores a hierarchical neural network structure to model words, clauses, and sentences at different levels, particularly with two layers of recurrent neural networks modeling semantic compositionality at the word and clause level. Correspondingly, the decoder sequentially translates segmented clauses and simultaneously applies two types of attention models to capture contexts of interclause and intraclause for translation prediction. In this way, we can not only improve parameter learning, but also well explore different scopes of contexts for translation. Experimental results on Chinese-English and English-German translation demonstrate the superiorities of the proposed model over the conventional NMT model.

2020-12-01
Yang, R., Ouyang, X., Chen, Y., Townend, P., Xu, J..  2018.  Intelligent Resource Scheduling at Scale: A Machine Learning Perspective. 2018 IEEE Symposium on Service-Oriented System Engineering (SOSE). :132—141.

Resource scheduling in a computing system addresses the problem of packing tasks with multi-dimensional resource requirements and non-functional constraints. The exhibited heterogeneity of workload and server characteristics in Cloud-scale or Internet-scale systems is adding further complexity and new challenges to the problem. Compared with,,,, existing solutions based on ad-hoc heuristics, Machine Learning (ML) has the potential to improve further the efficiency of resource management in large-scale systems. In this paper we,,,, will describe and discuss how ML could be used to understand automatically both workloads and environments, and to help to cope with scheduling-related challenges such as consolidating co-located workloads, handling resource requests, guaranteeing application's QoSs, and mitigating tailed stragglers. We will introduce a generalized ML-based solution to large-scale resource scheduling and demonstrate its effectiveness through a case study that deals with performance-centric node classification and straggler mitigation. We believe that an MLbased method will help to achieve architectural optimization and efficiency improvement.

2019-02-08
Kumar, Rajesh, Xiaosong, Zhang, Khan, Riaz Ullah, Ahad, Ijaz, Kumar, Jay.  2018.  Malicious Code Detection Based on Image Processing Using Deep Learning. Proceedings of the 2018 International Conference on Computing and Artificial Intelligence. :81-85.

In this study, we have used the Image Similarity technique to detect the unknown or new type of malware using CNN ap- proach. CNN was investigated and tested with three types of datasets i.e. one from Vision Research Lab, which contains 9458 gray-scale images that have been extracted from the same number of malware samples that come from 25 differ- ent malware families, and second was benign dataset which contained 3000 different kinds of benign software. Benign dataset and dataset vision research lab were initially exe- cutable files which were converted in to binary code and then converted in to image files. We obtained a testing ac- curacy of 98% on Vision Research dataset.

2018-12-10
Ma, L. M., IJtsma, M., Feigh, K. M., Paladugu, A., Pritchett, A. R..  2018.  Modelling and evaluating failures in human-robot teaming using simulation. 2018 IEEE Aerospace Conference. :1–16.

As robotic capabilities improve and robots become more capable as team members, a better understanding of effective human-robot teaming is needed. In this paper, we investigate failures by robots in various team configurations in space EVA operations. This paper describes the methodology of extending and the application of Work Models that Compute (WMC), a computational simulation framework, to model robot failures, interruptions, and the resolutions they require. Using these models, we investigate how different team configurations respond to a robot's failure to correctly complete the task and overall mission. We also identify key factors that impact the teamwork metrics for team designers to keep in mind while assembling teams and assigning taskwork to the agents. We highlight different metrics that these failures impact on team performance through varying components of teaming and interaction that occur. Finally, we discuss the future implications of this work and the future work to be done to investigate function allocation in human-robot teams.

2020-07-16
Mace, J.C., Morisset, C., Pierce, K., Gamble, C., Maple, C., Fitzgerald, J..  2018.  A multi-modelling based approach to assessing the security of smart buildings. Living in the Internet of Things: Cybersecurity of the IoT – 2018. :1—10.

Smart buildings are controlled by multiple cyber-physical systems that provide critical services such as heating, ventilation, lighting and access control. These building systems are becoming increasingly vulnerable to both cyber and physical attacks. We introduce a multi-model methodology for assessing the security of these systems, which utilises INTO-CPS, a suite of modelling, simulation, and analysis tools for designing cyber-physical systems. Using a fan coil unit case study we show how its security can be systematically assessed when subjected to Man-in-the-Middle attacks on the data connections between system components. We suggest our methodology would enable building managers and security engineers to design attack countermeasures and refine their effectiveness.

2018-12-10
Ross, Kevin, Moh, Melody, Moh, Teng-Sheng, Yao, Jason.  2018.  Multi-source Data Analysis and Evaluation of Machine Learning Techniques for SQL Injection Detection. Proceedings of the ACMSE 2018 Conference. :1:1–1:8.

SQL Injection continues to be one of the most damaging security exploits in terms of personal information exposure as well as monetary loss. Injection attacks are the number one vulnerability in the most recent OWASP Top 10 report, and the number of these attacks continues to increase. Traditional defense strategies often involve static, signature-based IDS (Intrusion Detection System) rules which are mostly effective only against previously observed attacks but not unknown, or zero-day, attacks. Much current research involves the use of machine learning techniques, which are able to detect unknown attacks, but depending on the algorithm can be costly in terms of performance. In addition, most current intrusion detection strategies involve collection of traffic coming into the web application either from a network device or from the web application host, while other strategies collect data from the database server logs. In this project, we are collecting traffic from two points: at the web application host, and at a Datiphy appliance node located between the webapp host and the associated MySQL database server. In our analysis of these two datasets, and another dataset that is correlated between the two, we have been able to demonstrate that accuracy obtained with the correlated dataset using algorithms such as rule-based and decision tree are nearly the same as those with a neural network algorithm, but with greatly improved performance.

2020-10-05
Cruz, Rodrigo Santa, Fernando, Basura, Cherian, Anoop, Gould, Stephen.  2018.  Neural Algebra of Classifiers. 2018 IEEE Winter Conference on Applications of Computer Vision (WACV). :729—737.

The world is fundamentally compositional, so it is natural to think of visual recognition as the recognition of basic visually primitives that are composed according to well-defined rules. This strategy allows us to recognize unseen complex concepts from simple visual primitives. However, the current trend in visual recognition follows a data greedy approach where huge amounts of data are required to learn models for any desired visual concept. In this paper, we build on the compositionality principle and develop an "algebra" to compose classifiers for complex visual concepts. To this end, we learn neural network modules to perform boolean algebra operations on simple visual classifiers. Since these modules form a complete functional set, a classifier for any complex visual concept defined as a boolean expression of primitives can be obtained by recursively applying the learned modules, even if we do not have a single training sample. As our experiments show, using such a framework, we can compose classifiers for complex visual concepts outperforming standard baselines on two well-known visual recognition benchmarks. Finally, we present a qualitative analysis of our method and its properties.

2019-10-30
Lewis, Matt.  2018.  Using Graph Databases to Assess the Security of Thingernets Based on the Thingabilities and Thingertivity of Things. Living in the Internet of Things: Cybersecurity of the IoT - 2018. :1-9.

Security within the IoT is currently below par. Common security issues include IoT device vendors not following security best practices and/or omitting crucial security controls and features within their devices, lack of defined and mandated IoT security standards, default IoT device configurations, missing secure update mechanisms to rectify security flaws discovered in IoT devices and the overall unintended consequence of complexity - the attack surface of networks comprising IoT devices can increase exponentially with the addition of each new device. In this paper we set out an approach using graphs and graph databases to understand IoT network complexity and the impact that different devices and their profiles have on the overall security of the underlying network and its associated data.

2019-02-08
Kılın\c c, H. H., Acar, O. F..  2018.  Analysis of Attack and Attackers on VoIP Honeypot Environment. 2018 26th Signal Processing and Communications Applications Conference (SIU). :1-4.

This work explores attack and attacker profiles using a VoIP-based Honeypot. We implemented a low interaction honeypot environment to identify the behaviors of the attackers and the services most frequently used. We watched honeypot for 180 days and collected 242.812 events related to FTP, SIP, MSSQL, MySQL, SSH, SMB protocols. The results provide an in-depth analysis about both attacks and attackers profile, their tactics and purposes. It also allows understanding user interaction with a vulnerable honeypot environment.

2020-11-23
Kumari, K. A., Sadasivam, G. S., Gowri, S. S., Akash, S. A., Radhika, E. G..  2018.  An Approach for End-to-End (E2E) Security of 5G Applications. 2018 IEEE 4th International Conference on Big Data Security on Cloud (BigDataSecurity), IEEE International Conference on High Performance and Smart Computing, (HPSC) and IEEE International Conference on Intelligent Data and Security (IDS). :133–138.
As 5G transitions from an industrial vision to a tangible, next-generation mobile technology, security remains key business driver. Heterogeneous environment, new networking paradigms and novel use cases makes 5G vulnerable to new security threats. This in turn necessitates a flexible and dependable security mechanism. End-to-End (E2E) data protection provides better security, avoids repeated security operations like encryption/decryption and provides differentiated security based on the services. E2E security deals with authentication, integrity, key management and confidentiality. The attack surface of a 5G system is larger as 5G aims for a heterogeneous networked society. Hence attack resistance needs to be a design consideration when defining new 5G protocols. This framework has been designed for accessing the manifold applications with high security and trust by offering E2E security for various services. The proposed framework is evaluated based on computation complexity, communication complexity, attack resistance rate and security defensive rate. The protocol is also evaluated for correctness, and resistance against passive, active and dictionary attacks using random oracle model and Automated Validation of Internet Security Protocols and Applications (AVISPA) tool.
2019-03-06
Suwansrikham, P., She, K..  2018.  Asymmetric Secure Storage Scheme for Big Data on Multiple Cloud Providers. 2018 IEEE 4th International Conference on Big Data Security on Cloud (BigDataSecurity), IEEE International Conference on High Performance and Smart Computing, (HPSC) and IEEE International Conference on Intelligent Data and Security (IDS). :121-125.

Recently, cloud computing is an emerging technology along with big data. Both technologies come together. Due to the enormous size of data in big data, it is impossible to store them in local storage. Alternatively, even we want to store them locally, we have to spend much money to create bit data center. One way to save money is store big data in cloud storage service. Cloud storage service provides users space and security to store the file. However, relying on single cloud storage may cause trouble for the customer. CSP may stop its service anytime. It is too risky if data owner hosts his file only single CSP. Also, the CSP is the third party that user have to trust without verification. After deploying his file to CSP, the user does not know who access his file. Even CSP provides a security mechanism to prevent outsider attack. However, how user ensure that there is no insider attack to steal or corrupt the file. This research proposes the way to minimize the risk, ensure data privacy, also accessing control. The big data file is split into chunks and distributed to multiple cloud storage provider. Even there is insider attack; the attacker gets only part of the file. He cannot reconstruct the whole file. After splitting the file, metadata is generated. Metadata is a place to keep chunk information, includes, chunk locations, access path, username and password of data owner to connect each CSP. Asymmetric security concept is applied to this research. The metadata will be encrypted and transfer to the user who requests to access the file. The file accessing, monitoring, metadata transferring is functions of dew computing which is an intermediate server between the users and cloud service.