Cloud Data Access Research Articles

The D-FCM partitioned D-BSP tree for massive point cloud data access and rendering

The spatial partitioning of massive point cloud data involves dividing the space into a multi-tree structure step by step, so as to achieve the purpose of fast access and to render the point cloud. The current methods are based on spatial regularity and equal division, which is not consistent with the irregular and non-uniform distribution of most point clouds. This paper presents a directional fuzzy c-means (D-FCM) method for irregular spatial partitioning. The distance metric is weighted by a direction coefficient, which is determined by the eigenvalue of the point cloud. The orientation of each node is adaptively calculated by principal component analysis of the point cloud, and Karhunen-Loeve (KL) transform is applied to the points coordinates in node. A binary space partitioning (BSP) tree structure is used to partition the point cloud data node by node, and a directional BSP (D-BSP) tree is formed. The D-BSP tree structure was tested with point clouds of 0.1 million to over 2 billion points (up to 60GB). The experimental results showed that the D-BSP tree can ensure that the bounding boxes are close to the actual spatial distribution of the point cloud, it can completely expand along the spatial configuration of the point cloud without generating unnecessary partitioning, and it can achieve a higher rendering speed with less memory requirement.

Rebuttal to “Comments on ‘Control Cloud Data Access Privilege and Anonymity With Fully Anonymous Attribute-Based Encryption”’

Ma et al. recently submitted a comment correspondence which points out a flaw in our paper (a sequel of our earlier paper published in the Proceedings of IEEE INFOCOM). The flaw led to the leakage of the system-wide master key; therefore, we improved our own scheme by addressing it.

Comments on “Control Cloud Data Access Privilege and Anonymity With Fully Anonymous Attribute-Based Encryption”

Most of the known attribute-based encryption (ABE) schemes focused on the data contents privacy and the access control, but less attention was paid to the privilege control and the identity privacy problem. Recently in IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY (TIFS) (DOI:10.1109/TIFS.2014.2368352), Jung <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> proposed an anonymous attribute-based encryption scheme for access privilege and anonymity, which exhibited a lot of interesting ideas and gave the proof in the standard model. However, after carefully revisiting the scheme, we found that any valid user can compute the system-wide master key and their proof has some mistakes, hence, it fails to meet their security definitions.

Controlling data access in cloud based on Multiple Level Attribute-set-based Encryption

Controlling data access in cloud based on Multiple Level Attribute-set-based Encryption

Flexible Data Access Control Based on Trust and Reputation in Cloud Computing

Cloud computing offers a new way of services and has become a popular service platform. Storing user data at a cloud data center greatly releases storage burden of user devices and brings access convenience. Due to distrust in cloud service providers, users generally store their crucial data in an encrypted form. But in many cases, the data need to be accessed by other entities for fulfilling an expected service, e.g., an eHealth service. How to control personal data access at cloud is a critical issue. Various application scenarios request flexible control on cloud data access based on data owner policies and application demands. Either data owners or some trusted third parties or both should flexibly participate in this control. However, existing work hasn't yet investigated an effective and flexible solution to satisfy this demand. On the other hand, trust plays an important role in data sharing. It helps overcoming uncertainty and avoiding potential risks. But literature still lacks a practical solution to control cloud data access based on trust and reputation. In this paper, we propose a scheme to control data access in cloud computing based on trust evaluated by the data owner and/or reputations generated by a number of reputation centers in a flexible manner by applying Attribue-Based Encryption and Proxy Re-Encryption. We integrate the concept of context-aware trust and reputation evaluation into a cryptographic system in order to support various control scenarios and strategies. The security and performance of our scheme are evaluated and justified through extensive analysis, security proof, comparison and implementation. The results show the efficiency, flexibility and effectiveness of our scheme for data access control in cloud computing.

Study of Controlling Cloud Data Access Privilege and Attribute Based Data Sharing with Attribute Revocation

Study of Controlling Cloud Data Access Privilege and Attribute Based Data Sharing with Attribute Revocation

Fault-Tolerance Techniques in Cloud Storage: A Survey

In recent years, cloud computing is highly embraced and more organizations consider at least some type of cloud strategy and apply theming their business process. Since failure is probable in cloud data centers and access to cloud resources available is fundamental, evaluation and application of different fault-tolerance methods is inevitable. On the other hand, the increasing growth of cloud storage users motivated us to study fault-tolerance techniques, and their strengths and weaknesses. In this paper, after introducing the concept off ault-tolerance in the context of cloud computing, the faulttolerant techniques are presented, and after introduction of some measures, a comparative analysis is provided.

Controlling Cloud Data Access Based on Reputation

Cloud computing offers a new way of service provision and will play an important role in the next generation mobile networks and services (in short 5G). Cloud data privacy and security protection is a crucial issue that impacts the success of cloud computing and may impede the development of 5G. Literature has proposed a number of cloud data access control schemes. However, existing solutions suffer from high computation complexity and cost and therefore few of them have been really deployed in practice. In this paper, we propose a practical scheme to securely access cloud data and effectively reduce access risk according to the reputations of cloud computing entities by applying proxy re-encryption in the situation that the data owner is not available online or does not know how to control the access. The advantages, security and performance of the proposed scheme are evaluated and justified through extensive analysis, security proof and implementation. The results show the efficiency and effectiveness of our scheme for practical deployment.

Transaction Management Techniques and Practices in Current Cloud Computing Environments : A Survey

Distributed database management systems (DBMSs)have limited capacity to manage overhead of distributed transactions due to certain failures. These types of failures don't guarantee the enforcement of transactional properties and which reduces the scalability and availability of these systems. Research in this area proved that scaling out whiling providing consistency of transactions and guaranteeing availability is the presence of different failures in distributed computing environment is not feasible. As a result, the database community have used vertical scaling rather than horizontal scaling. Moreover changes in data access patterns resulting from new generation of web applications with high scalability and availability guarantees weaker consistency. In this paper we have analyses that how different systems such as ElasTras, Mstore, Sinfonia, ecStore and Gstore provide scalable transactional data access in cloud computing environment. We have also discussed transactions management (TM) in Gstore in detail and compared with other techniques and protocols used in current cloud based systems.

Ensuring Security, Confidentiality and Fine-Grained Data Access Control of Cloud Data Storage Implementation Environment

With the development of cloud computing, the mutual understandability among distributed data access control has become an important issue in the security field of cloud computing. To ensure security, confidentiality and fine-grained data access control of Cloud Data Storage (CDS) environment, we proposed Multi-Agent System (MAS) architecture. This architecture consists of two agents: Cloud Service Provider Agent (CSPA) and Cloud Data Confidentiality Agent (CDConA). CSPA provides a graphical interface to the cloud user that facilitates the access to the services offered by the system. CDConA provides each cloud user by definition and enforcement expressive and flexible access structure as a logic formula over cloud data file attributes. This new access control is named as Formula-Based Cloud Data Access Control (FCDAC). Our proposed FCDAC based on MAS architecture consists of four layers: interface layer, existing access control layer, proposed FCDAC layer and CDS layer as well as four types of entities of Cloud Service Provider (CSP), cloud users, knowledge base and confidentiality policy roles. FCDAC, it’s an access policy determined by our MAS architecture, not by the CSPs. A prototype of our proposed FCDAC scheme is implemented using the Java Agent Development Framework Security (JADE-S). Our results in the practical scenario defined formally in this paper, show the Round Trip Time (RTT) for an agent to travel in our system and measured by the times required for an agent to travel around different number of cloud users before and after implementing FCDAC.

Control Cloud Data Access Privilege and Anonymity With Fully Anonymous Attribute-Based Encryption

Cloud computing is a revolutionary computing paradigm, which enables flexible, on-demand, and low-cost usage of computing resources, but the data is outsourced to some cloud servers, and various privacy concerns emerge from it. Various schemes based on the attribute-based encryption have been proposed to secure the cloud storage. However, most work focuses on the data contents privacy and the access control, while less attention is paid to the privilege control and the identity privacy. In this paper, we present a semianonymous privilege control scheme AnonyControl to address not only the data privacy, but also the user identity privacy in existing access control schemes. AnonyControl decentralizes the central authority to limit the identity leakage and thus achieves semianonymity. Besides, it also generalizes the file access control to the privilege control, by which privileges of all operations on the cloud data can be managed in a fine-grained manner. Subsequently, we present the AnonyControl-F, which fully prevents the identity leakage and achieve the full anonymity. Our security analysis shows that both AnonyControl and AnonyControl-F are secure under the decisional bilinear Diffie-Hellman assumption, and our performance evaluation exhibits the feasibility of our schemes.

Technology of Mobile Phone 3D Model Reconstruction Based on the Geomagic Studio

Studied the modeling strategy and application features of rapid surfacing reconstruction system. The 3D digital model reconstruction of real mobile phone as an example, using non-contact optical 3D scanning point cloud data access to mobile phone, get the mobile phone CAD model through data processing by point stage, polygon stage and shape stage, and the various stages of the process and the target are discussed in this paper.

SECURE DEPENDABLE SELECTIVE STORAGE SERVICES AND SUPPORT FOR DYNAMIC DATA OPERATIONS IN CLOUD COMPUTING

Cloud computing has been envisioned as the next generation architecture of IT enterprise. It moves the application software and databases to the centralized large data centers where management of data and services may not be fully trustworthy. This unique paradigm brings out many new security challenges like, maintaining correctness and integrity of data in cloud. Integrity of cloud data may be lost due to unauthorized access, modification or deletion of data. Lacking of availability of data may be due to the cloud service providers (CSP), in order to increase their margin of profit by reducing the cost, CSP may discard rarely accessed data without detecting in timely fashion. To overcome above issues, flexible distributed storage, token utilizing, signature creations used to ensure integrity of data, auditing mechanism used assists in maintaining the correctness of data and also locating, identifying of server where exactly the data has been corrupted and also dependability and availability of data achieved through distributed storage of data in cloud. Further in order to ensure authorized access to cloud data a admin module has been proposed in our previous conference paper, which prevents unauthorized users from accessing data and also selective storage scheme based on different parameters of cloud servers proposed in previous paper, in order to provide efficient storage of data in the cloud. In order to provide more efficiency in this paper dynamic data operations are supported such as updating, deletion and addition of data.