Most existing object-based storage systems rely on controllers or metadata servers to perform recovery [4, 18], or centrally micro-manage re-replication , failing to leverage intelli- gent storage devices. Other systems have adopted declus- tered replication strategies to distribute failure recovery, in- cluding OceanStore , Farsite , and Glacier . These systems focus primarily on data safety and secrecy (using erasure codes or, in the case of Farsite, encrypted replicas) and wide-area scalability (like CFS and PAST), but not per- formance. FAB (Federated Array of Bricks)  provides high performance by utilizing two-phase writes and voting among bricks to ensure linearizability and to respond to fail- ure and recovery. Although this improves tolerance to in- termittent failures, multiple bricks are required to ensure consistent read access, while the lack of complete knowledge of the data distribution further requires coordinator bricks to help conduct I/O. FAB can utilize both replication and erasure codes for efficient storage utilization, but relies on the use of NVRAM for good performance. In contrast, RA- DOS’s cluster maps drive consensus and ensure consistent access despite a simple and direct data access protocol. Xin et al.  conduct a quantitative analysis of reliabil- ity with FaRM, a declustered replication model in which— like RADOS—data objects are pseudo-randomly distributed among placement groups and then replicated by multiple OSDs, facilitating fast parallel recovery. They find that declustered replication improves reliability at scale, partic- ularly in the presence of relatively high failure rates for new disks (“infant mortality”). Lian et al.  find that relia- bility further depends on the number of placement groups per device, and that the optimal choice is related to the
ABSTRACT: Data de-duplication is one of the most important technique used for removing the identical copies of repeating data and it is used in the cloud storage for the purpose of reduce the storage space. Here only one copy for each file store. These files are owned by huge number of users. Keeping the multiple data copies with similar content de-duplication eliminates redundant data by keeping only one physical copy and refer other redundant data to that copy. Data de-duplication can be file level or block level. The duplicate copies of identical file eliminates by file level de- duplication. And block level de-duplication eliminates duplicate blocks of data that occur in non-identical files. In de- de-duplication storage space and bandwidth is reduced but reliability. This paper mainly concentrates on reducing storage while improving reliability, integrity and privacy of user’s sensitive data. File is divided into fragments using Secrete Sharing Scheme. This system allocates the file fragments using T-colouring graph technique. T.-Colouring allows to store the nodes at certain distance so prevents attacks like guessing location of fragments. To maintain integrity we are providing the Third Party Auditor scheme which makes the audit of file stored at cloud and notifies the data owner about file status stored at cloud server. This system supports security challenges such as authorized duplicate check, integrity, data confidentiality and reliability.
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for flash memory that is modeled with pulse-amplitude mod- ulation (PAM) plus Gaussian noise. We demonstrate that with the coded modulation, the storage reliability can be increased with the same signal-to-noise ratios (SNR). Furthermore, by performing the maximum a posteriori probability (MAP) decoding, we obtain soft information from TCM demodulator that can be utilized for LDPC decoding. Compared to flash memory with BCH coding, significant performance improve- ment of the concatenated system has been observed.
• Max. 320 GB formatted capacity per disk • Serial ATA 3.0Gbps Interface Support • SATA Native Command Queuing Feature • TuMR/PMR head with FOD technology • Load/Unload Head Technology • ATA Security Mode Feature Set • ATA S.M.A.R.T. Feature Set • SilentSeek™ • NoiseGuard™ • EcoSeek™
Service availability is most important in the cloud computing security. Amazon already mentions in its licensing agreement that it is possible that the service might be unavailable from time to time. The user’s web service may terminate for any reason at any time if any users files break the cloud storage policy. In addition, if any damage occurs to any Amazon web service and the service fails, in this case there will be no charge to the Amazon Company for this failure. Companies seeking to protect services from such failure need measures such as backups or use of multiple providers .
data reconstruction is expensive which makes this solution less attractive. Similarly, existing distributed storage systems based on near-optimal erasure codes  do not have an efficient solution for the data repair problem or pay no attention to it. Recently Chen et al.  proposed a network coding- based storage system which provides a decent solution for efficient data repair. This scheme, based on previous work , –, reduces the communication cost for data repair to the information theoretic minimum. This is achieved by recoding encoded packets in the healthy servers during the repair procedure. However, as network coding utilizes Gaussian elimination for decoding, the data retrieval in terms of computation cost is more expensive than erasure codes- based systems. Moreover,  adopts so-called functional repair for data repair, i.e., corrupted data is recovered to a correct form, but not the exact original form. While this is good for reducing data repair cost, it requires the data owner to produce new verification tags, e.g., cryptographic message authentication code, for newly generated data blocks. As the computational cost of generating verification tags is linear to the number of data blocks, this design will inevitably introduce heavy computation/communication cost on the data owner. Moreover, the data owner has to stay online during data repair. In this paper, we explore the problem of secure and reliablestorage in the “pay-as-you-use” cloud computing paradigm, and design a cloud storage service with the efficiency consider- ation of both data repair and data retrieval. By utilizing a near- optimal erasure codes, specifically LT codes, our designed storage service has faster decoding during data retrieval than existing solutions. To minimize the data repair complexity, we employ the exact repair method to efficiently recover the exact form of any corrupted data. Such a design also reduces the data owner’s cost during data repair since no verification tag needs to be generated (old verification tags can be recovered as data recovery). By enabling public integrity check, our designed LT codes based secure cloud storage service (LTCS) completely releases the data owner from the burden of being online. Our contributions are summarized as follows,
By analyzing data storage information in cloud environment, a multi-objective optimization model for reliablestorage is built. In view of data files with safety requirement stored by users, in the model, both data storage cost including storage price, migration cost and communication cost and data reliability including transmission reliability in storage process and storage device reliability after data storage are considered. In order to validate correctness and availability of the model, a multi-objective GA is designed under the framework of algorithm NSGA-II for model solution. In the experiments, computations are carried out through constructing several storage situations by using parameters published by existing commercial cloud storage services. The experimental results validate correctness and availability of the model, and show that the model can provide multiple storage solutions for users so that storage resources in DC can be effectively utilized.
Advantages: We provide formal definitions for RS- IBE and its corresponding safety model; we gift a concrete creation of RS-IBE. The proposed scheme can provide confidentiality and backward/forward2 secrecy simultaneously we show the security of the proposed scheme inside the trendy model, underneath the decisional ℓ-Bilinear Diffie-Hellman Exponent (ℓ-BDHE) assumption. In addition, the proposed scheme can resist decryption key exposure The manner of cipher text update best needs public facts. Note that no previous identity-based encryption schemes inside the literature can provide this selection; The additional computation and storage complexity, which are brought in by the forward secrecy, is all upper bounded by O(log(T )2), where T is the total number of time periods.
the other hand, storage scalability is minimal, as the full storage capacity is limited by the server node with the lowest capacity. Furthermore, adding new server nodes to the system does not increase storage capacity. On the other hand, with full distribution the system gives a lower reliability (a node failure makes some content unavailable) and request distribution needs to use some sort of directory service  to determine the node storing a file. However, storage scalability is maximum, as adding a new node means increasing the total amount of available storage.
comprehend cloud computing. A power company maintains and owns the infrastructure, a distribution company disseminates the electricity, and the consumers merely use the resources without the ownership or operational responsibilities. . It is a subscription-based service where networked storage space and computer resources can be obtained. One way to think of cloud computing is to be considered our experience with email. As the real-time requirement of data dissemination becomes increasingly significant in many fields, the emergency applications have received increasing attention, for instance, stock quote distribution, earthquake monitoring , emergency weather alert , smart transportation system , and social networks. Recently, the development of emergency applications demonstrates two trends. One is the sudden change of the arrival live content rate. Take ANSS  as an example, its mission is to provide real-time and accurate seismic information for emergency response personnel.
In  this paper they have presented the data security model of cloud computing considered on the learning of the cloud architecture. They have improved data security model and implemented software to increase work in a data security model and also apply this software in the Amazon EC2 micro instance. They have covered cloud computing overview its main attributes, service model, deployment models. Proposed model covers three layers of security with software, which compares eight modern encryption algorithms based on statistical test to get best secured algorithm. Now compare P-values with significance level α i.e. 0.01. If P-value >= αthen Accept the sequence else Reject the sequence. The higher P-value the better and vice versa with rejection rate, the lower the better. In  this paper he has presented the entire analysis of different symmetric key encryption algorithm like DES, CAST-128, 3DES, RC6, MARS, AES, IDEA, and Blowfish based on various parameters like Architecture, Scalability, Flexibility, Limitations , and Security. Performance of DES and CAST are equal, memory requisite by the AES and DES are the same but the performance of the AES is very high compare to DES. DES doesn’t support future modification. After evaluation, it is analyzed that AES is more secure, faster, better and useful encryption algorithm among all other algorithms by means of less storage space, high encryption performance without any weak point and limitation. In  these research papers they have examine two broad categories of cryptography like encoding & symmetric key encryption. And they also study a range of algorithms and evaluate them on the basis of performance & security. Performance of algorithm is evaluated based on parameters like file size, encryption time and encoding time. They have examined MD5 & SHA-256 encoding techniques and AES
The QNAP Turbo NAS is a complete backup solution that offers high performance storage to meet the needs of small or medium-sized businesses looking to simplify and centralize data management while safeguarding their data from unauthorized users. With powerful applications such as the NetBak Replicator, information can be automatically transferred from Windows PC to the NAS instantly or scheduled. The QNAP Turbo NAS is even an ideal storage for the Apple Time Machine. Many IT companies may already use third party software, and an array of backup software such as Acronis True image and Symantec Backup Exec is supported.
The availability of cheap identities results commonly in the whitewashing at- tack presented by free-riding (or selfish) peers. A free-riding peer conserves band- width and CPU by not contributing any resources to the system. Various incentive schemes have been proposed to encourage cooperation and participation in the net- work [17, 18]. One proven way for a system to deal with high churn is to distrust all newcomers in the system . However, with such a mechanism, legitimate new- comers are treated poorly initially, at least until they build a positive reputation. Feld- man et al. suggest a “stranger adaptive” strategy to counter whitewashing in a net- work . Using recent transactions with strangers, a peer estimates the probability of being cheated by the next stranger, and decides whether to trust the next stranger using that probability. Swamynathan et al. explore proactive firsthand reputations as a solution to generate quick and reliable reputations for short-lived network peers . We discuss this solution in greater detail in Sects. 3 and 4.
Before the delivering of the first lab test, the journey starts. It starts with making a calibration to the devices. Some devices might be programmed in advance to make a self-test every morning at a specific time and some devices ask the technician to make the calibration because it may require some reagents. Each workflow involving different consecutive steps that modify depending on the sample type and iterate the sample until it is contingent to extract its information and turn it into actionable results. Challenges are within every step promptly regarded to the sample type and analysis technologies, and at each step, there is a high risk for things to go in the wrong direction. Therefore, performing accurate quality control is of high importance to ensure quality results and reliable interpretation.
In this paper, an intelligent micro grid protection system using digital relaying with central control and monitoring infrastructure is proposed. Safety model is analyzed to improve protection level. Multifunctional Intelligent Digital Relay permits automatic adaptation of protection settings according to the actual type of grid structure and the interconnection of micro grid. These intelligent digital relays allow for continuous measure and monitor analog and digital signal originated from the system. Automated fault analysis is another important requirement for micro grid protection and safety. Modern microprocessor based/digital relay offer new approach based on pattern recognition and accurate fault location which are more reliable and secure than distance protection. The feasibility research on microgrid’s smart frequency and voltage control strategy in both the mode of isolated and grid-connected is mentioned.