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In cloud computing, attribute based encryption (ABE) is often used to solve the challenging issue in secure data storage. In order to lighten the burden of authority center, hierarchical ABE schemes is a very effective way. File hierarchy attribute based encryption (FH-CP-ABE) is a scheme, which both saves storage space of ciphertext and reduces the computation overhead of encryption. However, it's impossible to encrypt multiple files on the same access level in existing FH-CP-ABE scheme. The scheme is obviously not practical. In this paper, an efficient extended file hierarchy CP-ABE scheme (EFH-CP-ABE) is proposed, which can encrypt multiple files on the same access level. Our scheme is very practical especially for those big institutions or companies which have many hierarchical sectors, since it greatly saves storage space and computation cost for them on the cloud servers. Furthermore, our solution also achieves secure and flexible access control for users in cloud storage. We formally prove the security for our new scheme under the standard model. Finally, we implement the corresponding experiment for EFH-CP-ABE scheme and achieve desirable experimental results.

One of the most preferred encryption techniques for data sharing in cloud environment is Ciphertext-Policy Attribute Based Encryption (CP-ABE). An efficient File Hierarchy CP-ABE (FH-CP-ABE) scheme...

Prior work suggests that users conceptualize the organization of personal collections of digital files through the lens of similarity. However, it is unclear to what degree similar files are actually located near one another (e.g., in the same directory) in actual file collections, or whether leveraging file similarity can improve information retrieval and organization for disorganized collections of files. To this end, we conducted an online study combining automated analysis of 50 Google Drive and Dropbox users' cloud accounts with a survey asking about pairs of files from those accounts. We found that many files located in different parts of file hierarchies were similar in how they were perceived by participants, as well as in their algorithmically extractable features. Participants often wished to co-manage similar files (e.g., deleting one file implied deleting the other file) even if they were far apart in the file hierarchy. To further understand this relationship, we built regression models, finding several algorithmically extractable file features to be predictive of human perceptions of file similarity and desired file co-management. Our findings pave the way for leveraging file similarity to automatically recommend access, move, or delete operations based on users' prior interactions with similar files.

Secure Data Sharing enables account-to-account sharing of data through Snowflake database tables, secure views, and secure UDFs. With Secure Data Sharing, no actual data is copied or transferred between accounts. All sharing is accomplished through Snowflake’s unique services layer and metadata store. This is an important concept because it means that shared data does not take up any storage in a consumer account and, therefore, does not contribute to the consumer’s monthly data storage charges. The only charges to consumers are for the compute resources (i.e. virtual warehouses) used to query the shared data. Attribute-based encryption is a type of public-key encryption in which the secret key of a user and the cipher text are dependent upon attributes (e.g. the country in which he lives, or the kind of subscription he has). In such a system, the decryption of a cipher text is possible only if the set of attributes of the user key matches the attributes of the cipher text. There are mainly two types of attribute-based encryption schemes: Key-policy attribute-based encryption (KP-ABE) and cipher text-policy attribute-based encryption (CP-ABE). In KPABE, users’ secret keys are generated based on an access tree that defines the privileges scope of the concerned user, and data are encrypted over a set of attributes. However, CP-ABE uses access trees to encrypt data and users’ secret keys are generated over a set of attributes. Secure data sharing is a challenging problem currently being faced by the cloud computing sector. A novel method of Cipher text policy attribute based encryption (CP-ABE) is presented by paper to overcome the issues. The data from various sources like Medical and military sources, stored in the cloud, tend to have a multilevel hierarchy. But this hierarchy was not explored in CP-ABE.

Cloud technology is emerging as a widely accepted technology in the recent years due to its robust nature. Cloud computation is basically developed on the fact that the resources can be shared between numerous devices to achieve efficient network operation among devices with minimized computation expenses. However, the sharing nature poses a security risk for the devices whose resources are being shared. Almost in all the existing works on cloud security, a single trusted third party (TTP) is used for key issue and authorization. However, using a single TTP may results in single-point failure and security risks. Most of the previous works on cloud security focus on storage security rather than considering the computation security. In order to solve these issues, in this paper, multi-authority-based file hierarchy hidden CP-ABE scheme for cloud security is proposed. In this scheme, the files are arranged in hierarchical order based on their attribute weights. Then when a cloud user needs certain resources, it requests the cloud service provider (CSP). The CSP links with the cloud owner to provide the requested file after encrypting it. The cloud server encrypts and places the encrypted file in CSP, which is later retrieved by cloud user. In this way, all the files that are being used are encrypted along with strict authentication to ensure cloud security.

Wireless Body Area Networks (WBANs) play an important role in healthcare system by enabling medical experts to guide patients without measuring face-to-face. The unauthorized access of medical data from WBAN controller as well as the unreliable data communication may leads to risk for patients life. Currently, Chunqiang Hu et al., [1] proposed a data communication protocol by using Ciphertext-Policy Attribute-Based Encryption (CP-ABE) for a single file. The major limitation of Chunqiang Hu et al., [1] is that as the number of files increases, CP-ABE will suffer from parameters such as message size, energy consumption and computation cost. This paper proposes a more secure and efficient data communication protocol for WBANs by using an efficient File Hierarchy CP-ABE (FH-CP-ABE). We propose a more efficient Secure and Efficient data communication protocol for WBANs by using an efficient File Hierarchy CP-ABE (FH-CP-ABE). We use the integrated access structure which is a combination of two or more access structures and with the hierarchical files are encrypted. We evaluate the performance analysis of the proposed data communication protocol in terms of message size, energy consumption, computation cost and compared with Chunqiang Hu et al., [1] while the number of files increases.

E Healthcare system monitors the health condition and gives medical treatment through our web application. They collect the real time personal information PHI and patient's physical problem and transmitted it to the healthcare provider. To securely share the PHR information in cloud computing, a patient divides his PHR information M into two parts personal information m1 that may contain the patient's name, social security number, telephone number, home address, etc. The medical record m2 which does not contain sensitive personal information, such as medical test results, treatment protocols, and operation notes. Then the patient adopts CP ABE scheme to encrypt the information m1 and m2 by different access policies based on the actual need. Also we propose The Clinical Document Architecture CDA . Our CDA document integration system integrates multiple CDA documents per patient into a single CDA document and physicians and patients can browse the clinical data in chronological order and historical wise. Archana. P | Prasanna. S "An Efficient File Hierarchy based E-System with Clinical Document Architecture in Cloud Computing" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-2 , February 2018, URL: https://www.ijtsrd.com/papers/ijtsrd10785.pdf

With the rapid development of cloud computing technology, users tend to store their data remotely in the cloud to save storage space and enjoy scalable services. However, the cloud servers are not entirely trusted. Ciphertext-policy attribute-based encryption (CP-ABE) is considered as an effective cryptographic approach to prevent the untrusted cloud severs from leaking private data. Since in some areas such as medical and business, the shared data has the feature of multi-level hierarchy, so it makes sense to construct a hierarchy ABE scheme. Recently, Guo et al. proposed a PHR hierarchy multi-authority CP-ABE scheme, which implements global identifier (GID) hiding and hierarchical access control. Unfortunately, we find that the recursive operation (DecryptNode(CT, SK, (x, y))) defined in their scheme during the decryption phase is doubtable. Based on the analysis, we propose an improving file hierarchy MA-ABE scheme. The scheme preserves the security and privacy of the original scheme but reduces the user’s decryption overhead. In addition, we solve the shortcoming which exists in Guo’s scheme and the other corresponding schemes.

In this chapter we will create our First Azure Function usign Azure Portal as well as using Visual Studio Code. Also, we will look at the file hierarchy, configuration and settings of function.

Attribute-based encryption (ABE) can keep data privacy and realize fine-grained access control. However, the notion of file hierarchy hasn't been presented until now. The problem, the multiple hierarchical files to be shared only using once encryption scheme, cannot be effectively solved. Based on the access structure layered model, a novel access control scheme about file hierarchy is proposed by using ABE to solve the problem. The proposed scheme will not only decrease the number of access structures to one, but also only require a secret key to decrypt all the authorization files. It is proved to be secure against the chosen-plaintext attack (CPA) under the decision bilinear Diffie-Hellman (DBDH) assumption. In addition, the performance analysis results indicate that the proposed scheme is efficient and practical when a large number of hierarchical files are shared.

This paper discusses about types of file structures in Linux, points out that EXT2 is the most commonly used file system in Linux, analyzes the disk layout, index point and directory structure of EXT2, and studies the method to access files in EXT2 by name, which makes the access faster and more efficient.

BTRFS is a Linux filesystem that has been adopted as the default filesystem in some popular versions of Linux. It is based on copy-on-write, allowing for efficient snapshots and clones. It uses B-trees as its main on-disk data structure. The design goal is to work well for many use cases and workloads. To this end, much effort has been directed to maintaining even performance as the filesystem ages, rather than trying to support a particular narrow benchmark use-case. Linux filesystems are installed on smartphones as well as enterprise servers. This entails challenges on many different fronts. --- Scalability . The filesystem must scale in many dimensions: disk space, memory, and CPUs. --- Data integrity . Losing data is not an option, and much effort is expended to safeguard the content. This includes checksums, metadata duplication, and RAID support built into the filesystem. --- Disk diversity . The system should work well with SSDs and hard disks. It is also expected to be able to use an array of different sized disks, which poses challenges to the RAID and striping mechanisms. This article describes the core ideas, data structures, and algorithms of this filesystem. It sheds light on the challenges posed by defragmentation in the presence of snapshots, and the tradeoffs required to maintain even performance in the face of a wide spectrum of workloads.

As the fastest growing operating system, Linux is applied in broader areas, and more and more people start to use Linux operating system. In allusion to the hot issues like Linux and UnixLinux and free softwares, Linux kernelLinux DistroLinux and embedded systemLinux and WindowsLinux teaching, the research results have been summarized in the article.

MOOC is a massive open online course. In the MOOC all the files such as eBooks and PDF etc. are publicly visible to everyone. When the files are publicly visible to unauthorized domains they are said to be less secure. We propose a system where the files will be visible publicly for the other domains and cannot be downloaded and also hide the files which the author of a domain doesn't want to display publicly. Even though the files are visible to other domains they need to get the permission of the author of that particular domain. The author of that domain will generate a key on request based generation and deliver it to the requester. Only with the help of the key sent by the author the file can be downloaded. The file is encrypted and decrypted with the famous CP-ABE algorithm. To fight against unauthorized information leakage, sensitive data must to be encrypted before outsourcing so as to provide end to-end data confidentiality assurance in the cloud. Ordinary data encryption techniques prevent cloud from performing any meaningful operation of the underlying cipher text-policy, making the computation of encrypted data a very big problem. And interactive discussion forums to course videos in the Mooc will be incorporated. We propose a live video conferencing tool the MOOC. The proposed scheme achieves scalability due to its hierarchical structure and live interactions.

Due to present situation of equipment management in power plant, a development platform for equipment management application which is to achieve hot-plugging module has been presented. The functions of business framework platform and technology of hot-plugging module have also been introduced. Some base functions of business framework platform have been elaborated, such as design of base class, module management function, and menu authority management etc. How to plan module file hierarchy, plan function file hierarchy, design business page, release business module, and install or uninstall business module in the process of business development have been illustrated.

Properly booting, running, and securing your servers and PCs require well-designed and well-maintained partitions and filesystems. Partitions, as you’ve seen in previous chapters, are logically defined regions of a physical drive set aside for some particular use. Filesystems are structures used to organize files on a partition—or, for that matter, across multiple partitions—so that the files can be effectively accessed and secured.

Most bioinformatics software has been designed to run on Linux and other Unix-like systems. Unix is different from most desktop operating systems because it makes extensive use of a text-only command-line interface. It can be a challenge to become familiar with the command line, but once a person becomes used to it, there are significant rewards, such as the ability to string a commonly used series of commands together with a script. This appendix will get you started with the command line and other Unix essentials. © 2015 by John Wiley & Sons, Inc. Keywords: Linux; Unix; shell script; command line

This paper explains the construction of the filesystems which could be utilized in embedded systems as an implementation of ubiquitous computing. It includes the formal architecture of filesystem hierarchy for the DOC (Disk-On-Chip) filesystem and the flash filesystem based on the MTD (Memory Technology Devices). For DOC, the root filesystem and the user filesystem are constructed by the TrueFFS supported by the M-Systems. For MTD filesystem, the root filesystem is implemented in the fast RAM disk, and the user filesystem is implemented in the JFFS2 that supports large capacity. In order to support the GUI filesystem, the porting process of Qt/E is also included in this paper.

New VM instances are created from static templates that contain the basic configuration of the VM to achieve elasticity with regards to capacity. Instance specific settings can be injected into the VM during the deployment phase through means of contextualization. So far this is limited to a single data source and data remains static throughout the lifecycle of the VM. We present a layered approach to contextualization that supports different classes of contextualization data available from several sources. The settings are made available to the VM through virtual devices. Inside each VM data from different classes are layered on top of each other to create a unified file hierarchy. Context data can be modified during runtime by updating the contents of the virtual devices, making our approach the first contextualization approach to natively support recontextualization. Recontextualization enables runtime reconfiguration of an executing service and can act as a trigger and key enabler of self-* techniques. This trigger provides a service with a mechanism to adapt or optimize itself in response to a changing environment. The runtime reconfiguration using recontextualization and its potential gains are illustrated in an example with a distributed file system, demonstrating the feasibility of our approach.

This paper presents a new distributed disk-array architecture for achieving high I/O performance in scalable cluster computing. In a serverless cluster of computers, all distributed local disks can be integrated as a distributed-software redundant array of independent disks (ds-RAID) with a single I/O space. We report the new RAID-x design and its benchmark performance results. The advantage of RAID-x comes mainly from its orthogonal striping and mirroring (OSM) architecture. The bandwidth is enhanced with distributed striping across local and remote disks, while the reliability comes from orthogonal mirroring on local disks at the background. Our RAID-x design is experimentally compared with the RAID-5, RAID-10, and chained-declustering RAID through benchmarking on a research Linux cluster at USC. Andrew and Bonnie benchmark results are reported on all four disk-array architectures. Cooperative disk drivers and Linux extensions are developed to enable not only the single I/O space, but also the shared virtual memory and global file hierarchy. We reveal the effects of traffic rate and stripe unit size on I/O performance. Through scalability and overhead analysis, we find the strength of RAID-x in three areas: 1) improved aggregate I/O bandwidth especially for parallel writes, 2) orthogonal mirroring with low software overhead, and 3) enhanced scalability in cluster I/O processing. Architectural strengths and weakness of all four ds-RAID architectures are evaluated comparatively. The optimal choice among them depends on parallel read/write performance desired, the level of fault tolerance required, and the cost-effectiveness in specific I/O processing applications.

A storage performance analysis tool is very crucial to find performance bottlenecks of I/O storage systems and to develop efficient storage system architectures or algorithms. This paper presents an integrated performance analysis tool for the Linux filesystem. The tool provides the actual time information of functions of the Linux filesystem. Contrast to other existing tools, the tool provides with filtering capability, graphical interface, and system-level analysis information without any heavy load of measurement. Linux developers or end-users can utilize it for analyzing filesystem layers and measuring software performance to find out the bottleneck within the Linux filesystem.

The previous chapter provided a review of the useful analysis utilities available in Linux , so now is a good moment to provide an alternative view of the same topic. This time the focus will not be on the utilities per se, but rather on showing how some of the most frequently performed tasks can be completed.

Navigating through a file hierarchy is one of the most common methods for accessing files, yet it can be slow and repetitive. New algorithms that predict upcoming file accesses have the potential to improve navigation-based file retrieval, but it is unknown how best to present their predictions to users. We present three design goals aiming to improve navigation-based file retrieval interfaces: minimise the time spent at each hierarchical level en route to the target file; reduce the number of levels traversed by providing shortcuts; and promote rehearsal of the retrieval mechanics to facilitate expertise. We introduce three interfaces that augment standard file browsers based on each of these goals: Icon Highlights give greater prominence to predicted items in the current folder; Hover Menus provide shortcuts to predicted folder content; and Search Directed Navigation uses predictive highlighting to guide users through the hierarchy in response to query terms. Results from a user evaluation show that all three interfaces improve file retrieval times, with Icon Highlights and Hover Menus best suited for frequently accessed items and Search Directed Navigation best suited for infrequent ones. We also show that the benefits are larger when folder content is spatially unstable. Finally, we discuss how the interfaces could be combined and deployed in existing file browsers.

This paper mainly analyses Linux Security Module (LSM) and Virtual Filesystem of Linux. Based on the LSM security field & hooks, the method of marking subject and object sensitivity label is designed and implemented on Linux 2.6.26. This system meets GB17859–1999's requirements. In a simplified environment, it is completed that the system implements subject and object sensitivity label according to security policy by hooks.

One of the most fundamental issues in computer security is protecting sensitive files from unauthorized access. Traditional file protection tools run inside the target operating system, which hosts sensitive files. This makes previous approaches vulnerable in face of a compromised OS. To address this limitation, recent approaches seek for a good isolation by putting file system into a dedicated virtual machine or by using a network file system. However, they suffer a sharp increase in trusted computing base size which degrades their reliability.In this paper, we present Filesafe, a special purpose hy-pervisor aimed at protecting sensitive files in a compromised operating system. It bridges the semantic gap between guest OS and hypervisor by reconstructing file hierarchy from raw data, which incurs no runtime overhead. By enforcing security policies created in hypervisor, Filesafe could prevent sensitive files from unauthorized access even if they have kernel privileges in guest OS. We have implemented a proof-of-concept prototype on Windows XP with FAT32 file system. Furthermore, we evaluate Filesafe's performance and code size to demonstrate it is practical in real world scenarios.

In a compute cluster, the nodes may be distributed and heterogeneous in nature. It may be difficult to administer and interface with such a system. It will be better if all the users get an interface with same look and feel rather to have a different view in each node of the cluster. Thus Single System Image(SSI) is a major design goal of cluster based systems. The services that SSI clusters offer are single user interface, single process space, single memory space, single file hierarchy and single control point. Kerrighed is an SSI Operating System which provides the services mentioned above. This paper gives the details about how to set up a Kerrighed cluster, how to use a kerrighed cluster for running MPI programs, and shows how a cluster can improve the performance of an MPI program when it is run on a cluster of machines. The paper also gives an idea about how Kerrighed helps programmers to easily add new scheduling algorithms for cluster with the help of Scheduler API and a design for adding a proposed algorithm into Kerrighed.

Citation of scientific materials published on the Internet is often cumbersome because of unwieldy uniform resource locators (URLs). The authors describe a format for URLs that simplifies citation of scholarly materials. Its use depends on a simple HTML device, the “refresh page.” Uniform citation would follow this format: [Author I. Title of article. http://domain/year/month-day(e#).html ]. The HTML code for such a page is: . The code instructs the browser to suppress the content of the refresh page and bring up the title page of the cited article instead. Citations would be succinct and predictable. An electronic journal would not need to alter its existing file hierarchy but would need to establish a distinct domain name and maintain a file of refresh pages. Utilization of the “shadow” URL would bring us one step closer to truly universal resource locators.

Publisher Summary This chapter is an introduction to Unix in general and to Linux in particular, presenting some historical context and describing some fundamental aspects of the operating system architecture. As an operating system designed to be flexible and robust, Unix lends itself to providing a wide array of host- and network-based services. Linux and other Unix-like operating systems are prevalent on the Internet for a number of reasons. Linux is a bit of an oddball in the Unix operating system lineup. That's because, unlike the Unix versions released by the major vendors, Linux did not reuse any existing source code. Unix also has a rich culture from its long history as a fundamental part of computing research in industry and academia. Unix and related operating systems play a key role as platforms for delivering the key services that make the Internet possible. It is important that information security practitioners understand fundamental Unix concepts in support of practical knowledge of how Unix systems might be securely operated.

Publisher Summary Unix was originally conceived as a multiuser system, and as such, security could not be added on as an afterthought. In this respect, Unix was different from a whole class of computing machinery that had been targeted at single-user environments. It is vitally important to emphasize the need to keep Unix systems up to date. No operating system or other program can be considered safe without being patched up. Having a system with the latest security patches is the first and most often the best line of defense against intruders. All Unix systems have a patching mechanism; this is a way to get the system up to date. Depending on the vendor and the mechanism used, it is possible to “back out” the patches. Unix security has a long tradition, and though many concepts of the earliest Unix systems still apply, there have been a large number of changes that fundamentally altered the way the operating system implements these security principles. Most Unix systems allow restricting root logins to special terminals, typically the system console. This approach is quite effective, especially if the console or the allowed terminals are under strict physical access control. The obvious downside of this approach is that remote access to the system can be very limited. Using this approach, access through any TCP/IP-based connection cannot be configured, thus requiring a direct connection, such as a directly attached terminal or a modem.

Linux and UNIX systems can take advantage of the advanced manageability and reporting capabilities that Microsoft Operations Manager (MOM) 2005 already provides to Windows Server System technologies. It discusses some important points such as designing of an agentless solution to monitor and manage Linux and UNIX systems, installing the eXc Software Windows Management Instrumentation (WMI) non-Windows Event Provider and base framework, installing and configuring eXc Software Virtual Agents, customizing SNMP and CLI-based Virtual Agents, designing an agent-based solution to monitor and manage Linux and UNIX systems, installing the Jalasoft Xian 2005 Network Manager, installing the Xian UNIX Agent for Linux and Solarism, and configuring rules and policy templates to manage Linux and Solaris servers. The chapter also focuses on MOM 2005 that can be used to manage more than just Windows Server systems. Agentless solutions are growing in popularity and have changed the management paradigm that organizations use to monitor and control their critical infrastructure resources.

Dieses Kapitel stellt die gangigen Praktiken und Methodiken vor, mit deren Hilfe ein Unix- basiertes System auf Sicherheitslucken untersucht werden kann, und wie potentiell gefundene Schwachstellen ublicherweise ausgenutzt werden konnen, um Information zu stehlen oder aber das ganze System zu ubernehmen (oder zu kompromittieren, wie der Fachmann gerne sagt).

If the only thing you needed to learn about was Oracle database administration, your life would be so much easier. However, to ensure that your database perform efficiently, to it fullest, you will also need to have some understanding of the underlying operating system. In this chapter, you will examine the UNIX operating system.

We investigate filesystem support for continuous media on the Java language. We describe a prototype implementation on a Real-Time Java Server, developed as an application level server on the Real-Time Mach microkernel environment. The Java virtual machine has been extended to support filesystem bandwidth reservation facilities existing on Real-Time Mach. Such facilities allow continuous media applications to specify their disk bandwidth usage requirements by creating a disk bandwidth reservation. The operating system, upon acceptance of the requests, internally enforces and guarantees such a share of the disk bandwidth for every active reservation. We present a performance evaluation, including both a synthetic application and real multimedia application based on a QuickTime video player which make use of real time Java threads and filesystem bandwidth reservation facilities. Our experiments conclude that the proposed filesystem extensions to the Java language are suitable for continuous media application requirements.

Support of single system image (SSI) services is the main approach that enables better utilization of PC/workstation clusters. Some SSI services can be easily built with the support of other low-level, elementary, SSI services. In this paper, we describe a single I/O space architecture for achieving a SSI at the I/O subsystem level. Furthermore, we demonstrate how the single I/O space can facilitate the development of other key SSI services. Typical SSI services which can benefit from the single I/O space include single file hierarchy, single memory space, checkpointing systems and single process space with process migration facilities. Benchmark performance results show that our design achieves both performance and storage size scalabilities that are essential to building I/O-intensive clusters.