Circuit Ciphertext-Policy Attribute-Based Hybrid Encryption with Verifiable Delegation in Cloud Computing

ABSTRACT:

In the cloud, for achieving access control and keeping data confidential, the data owners could adopt attribute-based encryption to encrypt the stored data. Users with limited computing power are however more likely to delegate the mask of the decryption task to the cloud servers to reduce the computing cost. As a result, attribute-based encryption with delegation emerges. Still, there are caveats and questions remaining in the previous relevant works. For instance, during the delegation, the cloud servers could tamper or replace the delegated ciphertext and respond a forged computing result with malicious intent. They may also cheat the eligible users by responding them that they are ineligible for the purpose of cost saving. Furthermore, during the encryption, the access policies may not be flexible enough as well. Since policy for general circuits enables to achieve the strongest form of access control, a construction for realizing circuit ciphertext-policy attribute-based hybrid encryption with verifiable delegation has been considered in our work. In such a system, combined with verifiable computation and encrypt-then-mac mechanism, the data confidentiality, the fine-grained access control and the correctness of the delegated computing results are well guaranteed at the same time. Besides, our scheme achieves security against chosen-plaintext attacks under the k-multilinear Decisional Diffie-Hellman assumption. Moreover, an extensive simulation campaign confirms the feasibility and efficiency of the proposed solution.

EXISTING SYSTEM:

• The servers could be used to handle and calculate numerous data according to the user’s demands. As applications move to cloud computing platforms, ciphertext-policy attribute-based encryption (CP-ABE) and verifiable delegation (VD) are used to ensure the data confidentiality and the verifiability of delegation on dishonest cloud servers.
• The increasing volumes of medical images and medical records, the healthcare organizations put a large amount of data in the cloud for reducing data storage costs and supporting medical cooperation.
• There are two complementary forms of attribute based encryption. One is key-policy attribute-based encryption (KP-ABE) and the other is ciphertext-policy attribute-based encryption (CPABE).

DISADVANTAGES OF EXISTING SYSTEM:

• The cloud server might tamper or replace the data owner’s original ciphertext for malicious attacks, and then respond a false transformed ciphertext.
• The cloud server might cheat the authorized user for cost saving. Though the servers could not respond a correct transformed ciphertext to an unauthorized user, he could cheat an authorized one that he/she is not eligible.

PROPOSED SYSTEM:

• We firstly present a circuit ciphertext-policy attribute-based hybrid encryption with verifiable delegation scheme. General circuits are used to express the strongest form of access control policy.
• The proposed scheme is proven to be secure based on k-multilinear Decisional Diffie-Hellman assumption. On the other hand, we implement our scheme over the integers.
• During the delegation computing, a user could validate whether the cloud server responds a correct transformed ciphertext to help him/her decrypt the ciphertext immediately and correctly.

ADVANTAGES OF PROPOSED SYSTEM:

• The generic KEM/DEM construction for hybrid encryption which can encrypt messages of arbitrary length.
• They seek to guarantee the correctness of the original ciphertext by using a commitment.
• We give the anti-collusion circuit CP-ABE construction in this paper for the reason that CPABE is conceptually closer to the traditional access control methods.

SYSTEM ARCHITECTURE:

MODULES:

• Attribute Authority
• Cloud Server
• Data owner
• Data Consumer

MODULES DESCRIPTION:

1. Attribute Authority:

Authority will have to provide the key, as per the user’s key request. Every users request will have to be raised to authority to get access key on mail. There are two complementary forms of attribute-based encryption. One is key-policy attribute-based encryption (KP-ABE) and the other is ciphertext-policy attribute-based encryption (CPABE). In a KP-ABE system, the decision of access policy is made by the key distributor instead of the encipherer, which limits the practicability and usability for the system in practical applications.

2. Cloud Server:

Cloud server will have the access to files which are uploaded by the data owner

Cloud server needs to decrypt the files available under their permission.

Furthermore data user will have to decrypt the data to access the original text by providing the respective key. File has been decrypted successfully and provided for consumer.

3. Data owner:

Data owner will have to register initially to get access to the profile. Data Owner will upload the file to the cloud server in the encrypted format. Random encryption key generation is happening while uploading the file to the cloud. Encrypted file will be stored on the cloud.

4. Data Consumer:

Data consumer will initially ask for the key to the Authority to verify and decrypt the file in the cloud. Data consumer can access the file based on the key received from mail id. As per the key received the consumer can verify and decrypt the data from the cloud.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System : Pentium Dual Core.
• Hard Disk : 120 GB.
• Monitor : 15’’ LED
• Input Devices : Keyboard, Mouse
• Ram :

SOFTWARE REQUIREMENTS:

• Operating system : Windows 7.
• Coding Language : JAVA/J2EE
• Tool : Netbeans 7.2.1
• Database : MYSQL

REFERENCE:

Jie Xu, Qiaoyan Wen, Wenmin Li, and Zhengping Jin, “Circuit Ciphertext-Policy Attribute-Based Hybrid Encryption with Verifiable Delegation in Cloud Computing”, IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 27, NO. 1, JANUARY 2016.

ABSTRACT:

CDA Generation and Integration for Health Information Exchange Based on Cloud Computing System

Successful deployment of Electronic Health Record helps improve patient safety and quality of care, but it has the prerequisite of interoperability between Health Information Exchange at different hospitals. The Clinical Document Architecture (CDA) developed by HL7 is a core document standard to ensure such interoperability, and propagation of this document format is critical for interoperability. Unfortunately, hospitals are reluctant to adopt interoperable HIS due to its deployment cost except for in a handful countries. A problem arises even when more hospitals start using the CDA document format because the data scattered in different documents are hard to manage. In this paper, we describe our CDA document generation and integration Open API service based on cloud computing, through which hospitals are enabled to conveniently generate CDA documents without having to purchase proprietary software. 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. Our system of CDA document generation and integration is based on cloud computing and the service is offered in Open API. Developers using different platforms thus can use our system to enhance interoperability.

EXISTING SYSTEM:

• Effective health information exchange needs to be standardized for interoperable health information exchange between hospitals. Especially, clinical document standardization lies at the core of guaranteeing interoperability.
• It takes increasing amount of time for the medical personnel as the amount of exchanged CDA document increases because more documents means that data are distributed in different documents. This significantly delays the medical personnel in making decisions. Hence, when all of the CDA documents are integrated into a single document, the medical personnel is empowered to review the patient’s clinical history conveniently in chronological order per clinical section and the follow-up care service can be delivered more effectively. Unfortunately for now, a solution that integrates multiple CDA documents into one does not exist yet to the best of our knowledge and there is a practical limitation for individual hospitals to develop and implement a CDA document integration technology.

DISADVANTAGES OF EXISTING SYSTEM:

• The HIS development platforms for hospitals vary so greatly that generation of CDA documents in each hospital invariably requires a separate CDA generation system. Also, hospitals are very reluctant to adopt a new system unless it is absolutely necessary for provision of care. As a result, the adoption rate of EHR is very low except for in a few handful countries.
• Unfortunately for now, a solution that integrates multiple CDA documents into one does not exist yet to the best of our knowledge and there is a practical limitation for individual hospitals to develop and implement a CDA document integration technology.
• To establish confidence in HIE interoperability, more HIS’s need to support CDA. However, the structure of CDA is very complex and the production of correct CDA document is hard to achieve without deep understanding of the CDA standard and sufficient experience with it.

PROPOSED SYSTEM:

• In this paper we present (1) a CDA document generation system that generates CDA documents on different developing platforms and (2) a CDA document integration system that integrates multiple CDA documents scattered in different hospitals for each patient.
• CDA Generation API generates CDA documents on cloud.
• CDA Generation Interface uses the API provided by the cloud and relays the input data and receives
• CDA documents generated in the cloud.
• Template Manager is responsible for managing the CDA documents generated in the cloud server. Our system uses CCD document templates.
• CDA Generator collects patient data from hospitals and generates CDA documents in the template formats as suggested by the Template Manager.
• CDA Validator inspects whether the generated CDA document complies with the CDA schema standard.

ADVANTAGES OF PROPOSED SYSTEM:

• Hospital systems can simply extend their existing system rather than completely replacing it with a new system. Second, it becomes unnecessary for hospitals to train their personnel to generate, integrate, and view standard-compliant CDA documents.
• The cloud CDA generation service produces documents in the CDA format approved by the National Institute of Standards and Technology (NIST).
• If this service is provided for free at low price to hospitals, existing EHR are more likely to consider adoption of CDA in their practices.
• Interoperability between hospitals not only helps improve patient safety and quality of care but also reduce time and resources spent on data format conversion.

SYSTEM ARCHITECTURE:

CDA Generation and Integration for Health Information Exchange Based on Cloud Computing System

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System : Pentium Dual Core.
• Hard Disk : 120 GB.
• Monitor : 15’’ LED
• Input Devices : Keyboard, Mouse
• Ram : 1 GB

SOFTWARE REQUIREMENTS:

• Operating system : Windows 7.
• Coding Language : JAVA/J2EE
• Tool : Netbeans 7.2.1
• Database : MYSQL

REFERENCE:

Sung-Hyun Lee, Joon Hyun Song, and Il Kon Kim, “CDA Generation and Integration for Health Information Exchange Based on Cloud Computing System”, IEEE TRANSACTIONS ON SERVICES COMPUTING, VOL. 9, NO. 2, MARCH/APRIL 2016.

An Efficient Privacy-Preserving Ranked Keyword Search Method

ABSTRACT:

Cloud data owners prefer to outsource documents in an encrypted form for the purpose of privacy preserving. Therefore it is essential to develop efficient and reliable ciphertext search techniques. One challenge is that the relationship between documents will be normally concealed in the process of encryption, which will lead to significant search accuracy performance degradation. Also the volume of data in data centers has experienced a dramatic growth. This will make it even more challenging to design ciphertext search schemes that can provide efficient and reliable online information retrieval on large volume of encrypted data. In this paper, a hierarchical clustering method is proposed to support more search semantics and also to meet the demand for fast ciphertext search within a big data environment. The proposed hierarchical approach clusters the documents based on the minimum relevance threshold, and then partitions the resulting clusters into sub-clusters until the constraint on the maximum size of cluster is reached. In the search phase, this approach can reach a linear computational complexity against an exponential size increase of document collection. In order to verify the authenticity of search results, a structure called minimum hash sub-tree is designed in this paper. Experiments have been conducted using the collection set built from the IEEE Xplore. The results show that with a sharp increase of documents in the dataset the search time of the proposed method increases linearly whereas the search time of the traditional method increases exponentially. Furthermore, the proposed method has an advantage over the traditional method in the rank privacy and relevance of retrieved documents.

EXISTING SYSTEM:

• In the recent years, researchers have proposed many ciphertext search schemes by incorporating the cryptography techniques. In addition, the relationship between documents is concealed in the above methods. The relationship between documents represents the properties of the documents and hence maintaining the relationship is vital to fully express a document. For example, the relationship can be used to express its category. If a document is independent of any other documents except those documents that are related to sports, then it is easy for us to assert this document belongs to the category of the sports.
• Due to the blind encryption, this important property has been concealed in the traditional methods. Therefore, proposing a method which can maintain and utilize this relationship to speed the search phase is desirable.
• Sun et al. use Merkle hash tree and cryptographic signature to create a verifiable MDB-tree. However, their work cannot be directly used in our architecture which is oriented for privacy-preserving multiple keyword search. Thus, a proper mechanism that can be used to verify the search results within big data scenario is essential to both the CSPs and end users.

DISADVANTAGES OF EXISTING SYSTEM:

• Existing methods have been proven with provable security, but their methods need massive operations and have high time complexity. Therefore, former methods are not suitable for the big data scenario where data volume is very big and applications require online data processing.
• Song et al. method has a high searching cost due to the scanning of the whole data collection word by word.
• Due to the lack of rank mechanism, users have to take a long time to select what they want when massive documents contain the query keyword. Thus, the order-preserving techniques are utilized to realize the rank mechanism,
• Sun et al. give a new architecture which achieves better search efficiency. However, at the stage of index building process, the relevance between documents is ignored.

An Efficient Privacy-Preserving Ranked Keyword Search Method

PROPOSED SYSTEM:

• In this paper, a vector space model is used and every document is represented by a vector, which means every document can be seen as a point in a high dimensional space. Due to the relationship between different documents, all the documents can be divided into several categories.
• Instead of using the traditional sequence search method, a backtracking algorithm is produced to search the target documents. Cloud server will first search the categories and get the minimum desired sub-category. Then the cloud server will select the desired k documents from the minimum desired sub-category. The value of k is previously decided by the user and sent to the cloud server. If current sub-category can not satisfy the k documents, cloud server will trace back to its parent and select the desired documents from its brother categories. This process will be executed recursively until the desired k documents are satisfied or the root is reached.
• To verify the integrity of the search result, a verifiable structure based on hash function is constructed.

ADVANTAGES OF PROPOSED SYSTEM:

• The search time can be largely reduced by selecting the desired category and abandoning the irrelevant categories.
• Comparing with all the documents in the dataset, the number of documents which user aims at is very small. Due to the small number of the desired documents, a specific category can be further divided into several sub-categories.
• A virtual root is constructed to represent all the data and categories. The virtual root is denoted by the hash result of the concatenation of all the categories located in the first level. The virtual root will be signed so that it is verifiable. To verify the search result, user only needs to verify the virtual root, instead of verifying every document.

SYSTEM ARCHITECTURE:

An Efficient Privacy-Preserving Ranked Keyword Search Method

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System : Pentium Dual Core.
• Hard Disk : 120 GB.
• Monitor : 15’’ LED
• Input Devices : Keyboard, Mouse
• Ram : 1 GB

SOFTWARE REQUIREMENTS:

• Operating system : Windows 7.
• Coding Language : JAVA/J2EE
• Tool : Netbeans 7.2.1
• Database : MYSQL

REFERENCE:

Chi Chen, Member, IEEE, Xiaojie Zhu, Student Member, IEEE, Peisong Shen, Student Member, IEEE, Jiankun Hu, Member, IEEE, Song Guo, Senior Member, IEEE, Zahir Tari, Senior Member, IEEE, and Albert Y. Zomaya, Fellow, IEEE, “An Efficient Privacy-Preserving Ranked Keyword Search Method”, IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 27, NO. 4, APRIL 2016.

An Efficient File Hierarchy Attribute-Based Encryption Scheme in Cloud Computing

ABSTRACT:

Ciphertext-policy attribute-based encryption (CP-ABE) has been a preferred encryption technology to solve the challenging problem of secure data sharing in cloud computing. The shared data files generally have the characteristic of multilevel hierarchy, particularly in the area of healthcare and the military. However, the hierarchy structure of shared files has not been explored in CP-ABE. In this paper, an efficient file hierarchy attribute-based encryption scheme is proposed in cloud computing. The layered access structures are integrated into a single access structure, and then, the hierarchical files are encrypted with the integrated access structure. The ciphertext components related to attributes could be shared by the files. Therefore, both ciphertext storage and time cost of encryption are saved. Moreover, the proposed scheme is proved to be secure under the standard assumption. Experimental simulation shows that the proposed scheme is highly efficient in terms of encryption and decryption. With the number of the files increasing, the advantages of our scheme become more and more conspicuous.

EXISTING SYSTEM:

• Sahai and Waters proposed fuzzy Identity-Based Encryption (IBE) in 2005, which was the prototype of ABE. Latterly, a variant of ABE named CP-ABE was proposed.
• Since Gentry and Silverberg proposed the first notion of hierarchical encryption scheme, many hierarchical CP-ABE schemes have been proposed. For example, Wang et al. proposed a hierarchical ABE scheme by combining the hierarchical IBE and CP-ABE.
• Wan et al. proposed hierarchical ABE scheme. Later, Zou gave a hierarchical ABE scheme, while the length of secret key is linear with the order of the attribute set. A ciphertextpolicy hierarchical ABE scheme with short ciphertext is also studied.
• In these schemes, the parent authorization domain governs its child authorization domains and a top-level authorization domain creates secret key of the next-level domain. The work of key creation is distributed on multiple authorization domains and the burden of key authority center is lightened.

DISADVANTAGES OF EXISTING SYSTEM:

• In Existing System time and cost for encryption is high.
• No any special multiple hierarchical files are used.
• Decryption system time and computation cost are very high.

PROPOSED SYSTEM:

• In this study, an efficient encryption scheme based on layered model of the access structure is proposed in cloud computing, which is named file hierarchy CP-ABE scheme (or FH-CP-ABE, for short). FH-CP-ABE extends typical CP-ABE with a hierarchical structure of access policy, so as to achieve simple, flexible and fine-grained access control.
• The contributions of our scheme are three aspects.
• Firstly, we propose the layered model of access structure to solve the problem of multiple hierarchical files sharing. The files are encrypted with one integrated access structure.
• Secondly, we also formally prove the security of FH-CP-ABE scheme that can successfully resist chosen plaintext attacks (CPA) under the Decisional Bilinear Diffie-Hellman (DBDH) assumption.
• Thirdly, we conduct and implement comprehensive experiment for FH-CP-ABE scheme, and the simulation results show that FH-CP-ABE has low storage cost and computation complexity in terms of encryption and decryption.

ADVANTAGES OF PROPOSED SYSTEM:

• CP-ABE feasible schemes which has much more flexibility and is more suitable for general applications
• Multiple hierarchical files sharing are resolved using layered model of access structure.
• In proposed system both ciphertext storage and time cost of encryption are saved.
• The proposed scheme has an advantage that users can decrypt all authorization files by computing secret key once. Thus, the time cost of decryption is also saved if the user needs to decrypt multiple files.
• The computation cost of decryption can also be reduced if users need to decrypt multiple files at the same time.

SYSTEM ARCHITECTURE:

An Efficient File Hierarchy Attribute-Based Encryption Scheme in Cloud Computing

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System : Pentium Dual Core.
• Hard Disk : 120 GB.
• Monitor : 15’’ LED
• Input Devices : Keyboard, Mouse
• Ram : 1 GB

SOFTWARE REQUIREMENTS:

• Operating system : Windows 7.
• Coding Language : JAVA/J2EE
• Tool :         Netbeans 7.2.1
• Database : MYSQL

REFERENCE:

Shulan Wang, Junwei Zhou, Member, IEEE, Joseph K. Liu, Member, IEEE, Jianping Yu, Jianyong Chen, and Weixin Xie, “An Efficient File Hierarchy Attribute-Based Encryption Scheme in Cloud Computing”, IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY, VOL. 11, NO. 6, JUNE 2016.

A Secure Anti-Collusion Data Sharing Scheme for Dynamic Groups in the Cloud

A Secure Anti-Collusion Data Sharing Scheme for Dynamic Groups in the Cloud

ABSTRACT:

 Benefited from cloud computing, users can achieve an effective and economical approach for data sharing among group members in the cloud with the characters of low maintenance and little management cost. Meanwhile, we must provide security guarantees for the sharing data files since they are outsourced. Unfortunately, because of the frequent change of the membership, sharing data while providing privacy-preserving is still a challenging issue, especially for an untrusted cloud due to the collusion attack. Moreover, for existing schemes, the security of key distribution is based on the secure communication channel, however, to have such channel is a strong assumption and is difficult for practice. In this paper, we propose a secure data sharing scheme for dynamic members. Firstly, we propose a secure way for key distribution without any secure communication channels, and the users can securely obtain their private keys from group manager. Secondly, our scheme can achieve fine-grained access control, any user in the group can use the source in the cloud and revoked users cannot access the cloud again after they are revoked. Thirdly, we can protect the scheme from collusion attack, which means that revoked users cannot get the original data file even if they conspire with the untrusted cloud.   In our approach, by leveraging polynomial function, we can achieve a secure user revocation scheme. Finally, our scheme can achieve fine efficiency, which means previous users need not to update their private keys for the situation either a new user joins in the group or a user is revoked from the group.

EXISTING SYSTEM:

• Kallahalla et al presented a cryptographic storage system that enables secure data sharing on untrustworthy servers based on the techniques that dividing files into file groups and encrypting each file group with a file-block key.
• Yu et al exploited and combined techniques of key policy attribute-based encryption, proxy re-encryption and lazy re-encryption to achieve fine-grained data access control without disclosing data contents.

DISADVANTAGES OF EXISTING SYSTEM:

• The file-block keys need to be updated and distributed for a user revocation; therefore, the system had a heavy key distribution overhead.
• The complexities of user participation and revocation in these schemes are linearly increasing with the number of data owners and the revoked users.
• The single-owner manner may hinder the implementation of applications, where any member in the group can use the cloud service to store and share data files with others.

PROPOSED SYSTEM:

• In this paper, we propose a secure data sharing scheme, which can achieve secure key distribution and data sharing for dynamic group.
• We provide a secure way for key distribution without any secure communication channels. The users can securely obtain their private keys from group manager without any Certificate Authorities due to the verification for the public key of the user.
• Our scheme can achieve fine-grained access control, with the help of the group user list, any user in the group can use the source in the cloud and revoked users cannot access the cloud again after they are revoked.
• We propose a secure data sharing scheme which can be protected from collusion attack. The revoked users can not be able to get the original data files once they are revoked even if they conspire with the untrusted cloud. Our scheme can achieve secure user revocation with the help of polynomial function.
• Our scheme is able to support dynamic groups efficiently, when a new user joins in the group or a user is revoked from the group, the private keys of the other users do not need to be recomputed and updated.
• We provide security analysis to prove the security of our scheme.

ADVANTAGES OF PROPOSED SYSTEM:

• The computation cost is irrelevant to the number of revoked users in RBAC scheme. The reason is that no matter how many users are revoked, the operations for members to decrypt the data files almost remain the same.
• The cost is irrelevant to the number of the revoked users. The reason is that the computation cost of the cloud for file upload in our scheme consists of two verifications for signature, which is irrelevant to the number of the revoked users. The reason for the small computation cost of the cloud in the phase of file upload in RBAC scheme is that the verifications between communication entities are not concerned in this scheme.
• In our scheme, the users can securely obtain their private keys from group manager Certificate Authorities and secure communication channels. Also, our scheme is able to support dynamic groups efficiently, when a new user joins in the group or a user is revoked from the group, the private keys of the other users do not need to be recomputed and updated.

SYSTEM ARCHITECTURE:

A Secure Anti-Collusion Data Sharing Scheme for Dynamic Groups in the Cloud

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System :         Pentium IV 2.4 GHz.
• Hard Disk :         40 GB.
• Floppy Drive : 44 Mb.
• Monitor : 15 VGA Colour.
• Mouse :
• Ram : 512 Mb.

SOFTWARE REQUIREMENTS:

• Operating system : Windows XP/7.
• Coding Language : JAVA/J2EE
• IDE : Netbeans 7.4
• Database : MYSQL

REFERENCE:

Zhongma Zhu and Rui Jiang, “A Secure Anti-Collusion Data Sharing Scheme for Dynamic Groups in the Cloud”, IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 27, NO. 1, JANUARY 2016.

A Secure and Dynamic Multi-Keyword Ranked Search Scheme over Encrypted Cloud Data

ABSTRACT (Secure Dynamic Multi-Keyword Ranked Search Scheme Encrypted Cloud Data):

Secure Dynamic Multi-Keyword Ranked Search Scheme Encrypted Cloud Data. Due to the increasing popularity of cloud computing, more and more data owners are motivated to outsource their data to cloud servers for great convenience and reduced cost in data management. However, sensitive data should be encrypted before outsourcing for privacy requirements, which obsoletes data utilization like keyword-based document retrieval. In this paper, we present a secure multi-keyword ranked search scheme over encrypted cloud data, which simultaneously supports dynamic update operations like deletion and insertion of documents. Specifically, the vector space model and the widely-used TF _ IDF model are combined in the index construction and query generation. We construct a special tree-based index structure and propose a “Greedy Depth-first Search” algorithm to provide efficient multi-keyword ranked search. The secure kNN algorithm is utilized to encrypt the index and query vectors, and meanwhile ensure accurate relevance score calculation between encrypted index and query vectors. In order to resist statistical attacks, phantom terms are added to the index vector for blinding search results. Due to the use of our special tree-based index structure, the proposed scheme can achieve sub-linear search time and deal with the deletion and insertion of documents flexibly. Extensive experiments are conducted to demonstrate the efficiency of the proposed scheme.

EXISTING SYSTEM:

• A general approach to protect the data confidentiality is to encrypt the data before outsourcing.
• Searchable encryption schemes enable the client to store the encrypted data to the cloud and execute keyword search over ciphertext domain. So far, abundant works have been proposed under different threat models to achieve various search functionality, such as single keyword search, similarity search, multi-keyword boolean search, ranked search, multi-keyword ranked search, etc. Among them, multi-keyword ranked search achieves more and more attention for its practical applicability. Recently, some dynamic schemes have been proposed to support inserting and deleting operations on document collection. These are significant works as it is highly possible that the data owners need to update their data on the cloud server.

DISADVANTAGES OF EXISTING SYSTEM:

• Huge cost in terms of data usability. For example, the existing techniques on keyword-based information retrieval, which are widely used on the plaintext data, cannot be directly applied on the encrypted data. Downloading all the data from the cloud and decrypt locally is obviously impractical.
• Existing System methods not practical due to their high computational overhead for both the cloud sever and user.

PROPOSED SYSTEM:

• This paper proposes a secure tree-based search scheme over the encrypted cloud data, which supports multi-keyword ranked search and dynamic operation on the document collection. Specifically, the vector space model and the widely-used “term frequency (TF) × inverse document frequency (IDF)” model are combined in the index construction and query generation to provide multi-keyword ranked search. In order to obtain high search efficiency, we construct a tree-based index structure and propose a “Greedy Depth-first Search” algorithm based on this index tree.
• The secure kNN algorithm is utilized to encrypt the index and query vectors, and meanwhile ensure accurate relevance score calculation between encrypted index and query vectors.
• To resist different attacks in different threat models, we construct two secure search schemes: the basic dynamic multi-keyword ranked search (BDMRS) scheme in the known ciphertext model, and the enhanced dynamic multi-keyword ranked search (EDMRS) scheme in the known background model.

ADVANTAGES OF PROPOSED SYSTEM:

• Due to the special structure of our tree-based index, the proposed search scheme can flexibly achieve sub-linear search time and deal with the deletion and insertion of documents.
• We design a searchable encryption scheme that supports both the accurate multi-keyword ranked search and flexible dynamic operation on document collection.
• Due to the special structure of our tree-based index, the search complexity of the proposed scheme is fundamentally kept to logarithmic. And in practice, the proposed scheme can achieve higher search efficiency by executing our “Greedy Depth-first Search” algorithm. Moreover, parallel search can be flexibly performed to further reduce the time cost of search process.

SYSTEM ARCHITECTURE:

Secure Dynamic Multi-Keyword Ranked Search Scheme Encrypted Cloud Data

MODULES

• Data Owner Module
• Data User Module
• Cloud server and Encryption Module
• Rank Search Module

Secure Dynamic Multi-Keyword Ranked Search Scheme Encrypted Cloud Data

MODULES DESCRIPTION

Data Owner Module

This module helps the owner to register those details and also include login details. This module helps the owner to upload his file with encryption using RSA algorithm. This ensures the files to be protected from unauthorized user. Data owner has a collection of documents F ={f1; f2; :::; fn} that he wants to outsource to the cloud server in encrypted form while still keeping the capability to search on them for effective utilization. In our scheme, the data owner firstly builds a secure searchable tree index I from document collection F, and then generates an encrypted document collection C for F. Afterwards, the data owner outsources the encrypted collection C and the secure index I to the cloud server, and securely distributes the key information of trapdoor generation and document decryption to the authorized data users. Besides, the data owner is responsible for the update operation of his documents stored in the cloud server. While updating, the data owner generates the update information locally and sends it to the server.

Data User Module

This module includes the user registration login details. This module is used to help the client to search the file using the multiple key words concept and get the accurate result list based on the user query. The user is going to select the required file and register the user details and get activation code in mail email before enter the activation code. After user can download the Zip file and extract that file. Data users are authorized ones to access the documents of data owner. With t query keywords, the authorized user can generate a trapdoor TD according to search control mechanisms to fetch k encrypted documents from cloud server. Then, the data user can decrypt the documents with the shared secret key.

Cloud Server and Encryption Module:

This module is used to help the server to encrypt the document using RSA Algorithm and to convert the encrypted document to the Zip file with activation code and then activation code send to the user for download. Cloud server stores the encrypted document collection C and the encrypted searchable tree index I for data owner. Upon receiving the trapdoor TD from the data user, the cloud server executes search over the index tree I, and finally returns the corresponding collection of top- k ranked encrypted documents. Besides, upon receiving the update information from the data owner, the server needs to update the index I and document collection C according to the received information. The cloud server in the proposed scheme is considered as “honest-but-curious”, which is employed by lots of works on secure cloud data search

Rank Search Module

These modules ensure the user to search the files that are searched frequently using rank search. This module allows the user to download the file using his secret key to decrypt the downloaded data. This module allows the Owner to view the uploaded files and downloaded files. The proposed scheme is designed to provide not only multi-keyword query and accurate result ranking, but also dynamic update on document collections. The scheme is designed to prevent the cloud server from learning additional information about the document collection, the index tree, and the query.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System : Pentium Dual Core.
• Hard Disk : 120 GB.
• Monitor : 15’’ LED
• Input Devices : Keyboard, Mouse
• Ram : 1GB.

SOFTWARE REQUIREMENTS:

• Operating system : Windows 7.
• Coding Language : JAVA/J2EE
• Tool : Netbeans 7.2.1
• Database : MYSQL

Secure Dynamic Multi-Keyword Ranked Search Scheme Encrypted Cloud Data

REFERENCE:

Zhihua Xia, Member, IEEE, Xinhui Wang, Xingming Sun, Senior Member, IEEE, and Qian Wang, Member, IEEE, “A Secure and Dynamic Multi-Keyword Ranked Search Scheme over Encrypted Cloud Data”, IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 27, NO. 2, FEBRUARY 2016