Secure Auditing and Deduplicating Data in Cloud

by | Aug 14, 2015 | Uncategorized | 0 comments

Secure Auditing and Deduplicating  Data in Cloud

 

ABSTRACT:

As the cloud computing technology develops during the last decade, outsourcing data to cloud service for storage becomes an attractive trend, which benefits in sparing efforts on heavy data maintenance and management. Nevertheless, since the outsourced cloud storage is not fully trustworthy, it raises security concerns on how to realize data deduplication in cloud while achieving integrity auditing. In this work, we study the problem of integrity auditing and secure deduplication on cloud data. Specifically, aiming at achieving both data integrity and deduplication in cloud, we propose two secure systems, namely SecCloud and SecCloud+. SecCloud introduces an auditing entity with a maintenance of a MapReduce cloud, which helps clients generate data tags before uploading as well as audit the integrity of data having been stored in cloud. Compared with previous work, the computation by user in SecCloud is greatly reduced during the file uploading and auditing phases. SecCloud+ is designed motivated by the fact that customers always want to encrypt their data before uploading, and enables integrity auditing and secure deduplication on encrypted data.

 

EXISTING SYSTEM:

SecCloud introduces an auditing entity with a maintenance of a Map Reduce cloud, which helps clients generate data tags before uploading as well as audit the integrity of data having been stored in cloud. This design fixes the issue of previous work that the computational load at user or auditor is too huge for tag generation. For completeness of fine-grained, the functionality of auditing designed in SecCoud is supported on both block level and sector level. In addition, SecCoud also enables secure deduplication. Notice that the “security” considered in SecCoud is the prevention of leakage of side channel information. In order to prevent the leakage of such side channel information, we follow the tradition of and design a proof of ownership protocol between clients and cloud servers, which allows clients to prove to cloud servers that they exactly own the target data.

Motivated by the fact that customers always want to encrypt their data before uploading, for reasons ranging from personal privacy to corporate policy, we introduce a key server into SecCloud as with and propose the SecCloud+ schema. Besides supporting integrity auditing and secure deduplication, SecCloud+ enables the guarantee of file confidentiality. Specifically, thanks to the property of deterministic encryption in convergent encryption, we propose a method of directly auditing integrity on encrypted data. The challenge of deduplication on encrypted is the prevention of dictionary attack. As with, we make a modification on convergent encryption such that the convergent key of file is generated and controlled by a secret “seed”, such that any adversary could not directly derive the convergent key from the content of file and the dictionary attack is prevented.

Disadvantages :

  • It is very difficult to audit the files huge and large amount of data in cloud using integrity auditing.
  • Data loss and lots of Duplicate files in cloud .

PROPOSED SYSTEM:

We specify that our proposed SecCloud system has achieved both integrity auditing and file deduplication. However, it cannot prevent the cloud servers from knowing the content of files having been stored. In other words, the functionalities of integrity auditing and secure deduplication are only imposed on plain files. In this section, we propose SecCloud+, which allows for integrity auditing and deduplication on encrypted files. Cloud Clients have large data files to be stored and rely on the cloud for data maintenance and computation. They can be either individual consumers or commercial organizations;

Cloud Servers virtualize the resources according to the requirements of clients and expose them as storage pools. Typically, the cloud clients may buy or lease storage capacity from cloud servers, and store their individual data in these bought or rented spaces for future utilization.  Auditor which helps clients upload and audit their outsourced data maintains a MapReduce cloud and acts like a certificate authority. This assumption presumes that the auditor is associated with a pair of public and private keys. Its public key is made available to the other entities in the system

The design goal of file confidentiality requires to prevent the cloud servers from accessing the content of files. Specially, we require that the goal of file confidentiality needs to be resistant to “dictionary attack”. That is, even the adversaries have pre-knowledge of the “dictionary” which includes all the possible files, they still cannot recover the target file.


 

Advantages:

  • It provides the Integrity auditing by Clustering the files with removing the duplicate files
  • The duplicate files are mapped with a single copy of the file by mapping with the existing file in the cloud

MODULE DESCRIPTION:

File Confidentiality:

The design goal of file confidentiality requires to prevent the cloud servers from accessing the content of files. Specially, we require that the goal of file confidentiality needs to be resistant to “dictionary attack”. That is, even the adversaries have pre-knowledge of the “dictionary” which includes all the possible files, they still cannot recover the target file

Secure Deduplication:

Deduplication is a technique where the server stores only a single copy of each file, regardless of how many clients asked to store that file, such that the disk space of cloud servers as well as network bandwidth are saved. However, trivial client side deduplication leads to the leakage of side channel information. For example, a server telling a client that it need not send the file reveals that some other client has the exact same file, which could be sensitive information in some case.

Encryption & Decryption:

Encryption  and decryption provides data confidentiality in deduplication.  A user (or data owner) derives a convergent key from the data content and encrypts the data copy with the convergent key. In addition, the user derives a tag for the data copy, such that the tag will be used to detect duplicates. Here, we assume that the tag correctness property holds, i.e., if two data copies are the same, then their tags are the same. Formally, a convergent encryption scheme can be defined with four primitive functions:


 

Integrity Auditing:

The first design goal of this work is to provide the capability of verifying correctness of the remotely stored data. The integrity verification further requires two features:

  1. Public verification, which allows anyone, not just the clients originally stored the file, to perform verification;
  1. Stateless verification, which is able to eliminate the need for state information maintenance at the verifier side between the actions of auditing and data storage.

ARCHITECTURE

 


 

 

 

CONCLUSION:

Aiming at achieving both data integrity and deduplication in cloud, we propose SecCloud and SecCloud+. SecCloud introduces an auditing entity with maintenance of a MapReduce cloud, which helps clients generate data tags before uploading as well as audit the integrity of data having been stored in cloud. In addition, SecCoud enables secure deduplication through introducing a Proof of Ownership protocol and preventing the leakage of side channel information in data deduplication. Compared with previous work, the computation by user in SecCloud is greatly reduced during the file uploading and auditing phases. SecCloud+ is an advanced construction motivated by the fact that customers always want to encrypt their data before uploading, and allows for integrity auditing and secure deduplication directly on encrypted data.