Improving Data Sharing Security in Cloud Computing

IJEER, 2021

The field of data management has been reformed by the Cloud computing technologies which offered valuable establishments and amended the storage restrictions barriers for its users. In large enterprises the cloud has been extensively used for implementation due to its benefits. There are still lot of security threats for the data in the cloud. The data owners suffer from its privacy issues which are considered as one of the major concerns. Data privacy can be secured by employing some of the existing methods such as Attribute-based Encryption (ABE). Yet, the security issues are prevailing largely over the cloud. In this research a secured data access control is proposed using the Advanced Encryption Standard (AES) combined with a weighted attribute-based Encryption (AES-WABE). To encrypt the data, the access control policies are used and weight is assigned according to its significance of each attribute. The outsourced data is stored by the cloud service provider and the attribute authority based on the weight that updates the attributes. To minimize the computational overload the data file is accessed by the receiver corresponding to its weight. The proposed procedure provides resistance for collusion, multiple user security with control of fine-grained access based on protection, reliability and efficiency. On concerning the data collaboration and confidentiality, the performance rating is done related with the Cipher-text Policy-Attribute-based Encryption (CP-ABE) and the hybrid attribute-based encryption (HABE) scheme, access control flexibility, limited decryption, full delegation, verification and partial signing.

Cloud security is the most critical task while considering its working environment, i.e. outsourced, distributed and utility based. In such cases making the users data confidential, increases the trust over the system. Also the security procedure does not make the availability affected in any ways. The users of these kind of systems is always retained the services and securities preliminaries with respect to the data itself. As the cloud user can access its data frequently and if here some encryption is used which requires decryption and the repetitive process continues to increase the overheads. It requires some mechanism in which encryption is performed and if the user requires to perform some operations on secure file without decrypting it can be fulfilled. Thus homomorphic encryption lets the user facilitates about the performing operations on encrypted data which reduces the complexity of confidentiality operations. Also to prevent Cloud Servers from being able to learn both the data file contents and user access privilege information used to generate key along with the fastest access of secured data by using Attribute-based encryption (ABE).

2015

Cloud computing is an emerging computing paradigm, enabling users to store their data remotely in a server and to provide services on-demand. In cloud computing, cloud users and cloud service providers are almost clear from different trust domains. The critical issues for remote data storage are data security and privacy. A secure user enforced the data access control and that mechanism must be provided before the cloud users have liberty to outsource delicate data to cloud for storage. With the emergence of sharing personal data on cloud servers, it is essential to acquire an efficient encryption system with a fine-grained access control to encrypt outsourced data. Attribute-Based Encryption is a public key based encryption that enables access control over encrypted data using access policies and ascribed attributes. In this paper, we are going to analyze various schemes for encryption and possible solutions for their limitations that consist of Attribute Based Encryption (ABE), CP...

Cloud computing is an emerging computing paradigm, enabling users to store their data remotely in a server and to provide services on-demand. In cloud computing, cloud users and cloud service providers are almost clear from different trust domains. The critical issues for remote data storage are data security and privacy. A secure user enforced the data access control and that mechanism must be provided before the cloud users have liberty to outsource delicate data to cloud for storage. With the emergence of sharing personal data on cloud servers, it is essential to acquire an efficient encryption system with a fine-grained access control to encrypt outsourced data. Attribute-Based Encryption is a public key based encryption that enables access control over encrypted data using access policies and ascribed attributes. In this paper, we are going to analyze various schemes for encryption and possible solutions for their limitations that consist of Attribute Based Encryption (ABE), CP-ABE, HABE, MA-ABE, KP-ABE

2014

As more sensitive data is shared and stored by third-party sites on the Internet, the data in these sites will need to encrypt. The main drawback of encrypting data is that it can be selectively shared only at a coarse-grained level (i.e., giving another party your private key). We progress a new cryptosystem for fine-grained sharing of reencrypted data that we call Key-Policy Attribute-Based Encryption (KP-ABE). In our cryptosystem, cipher texts are labeled with sets of attributes and private keys are associated with access structures that control which cipher texts a user is able to decrypt. We explain the applicability of our construction to sharing of audit-log information and broadcast re-encryption with TPA(third Party Auditor). Our analysis supports delegation of private keys which subsumes Hierarchical Identity-Based Re-Encryption (HIBR).

Due to the rapid growth in networks communication security issue are being a challenging task. In this project deep analysis is to be made in the cyber security using proxy re-encryption and cipher text crypto system. Various algorithm are been proposed for the cipher text encryption and decryption in decentralized mobile networks with mobile user policy. Based on the existing study it is to propose a new algorithm for encryption and decryption. Ciphertext-policy attribute-based encryption scheme delegating attribute revocation process to cloud server by proxy re-encryption. The proposed scheme does not require secret sharing schemes (LSSS) access structure. Proposed scheme is secure against attack by unauthorized users and cloud server. Sharing of the cloud storage has a risk of information leakage caused by service. In order the protect data, the data owner encrypts data shared on the cloud storage so that only authorized users can decrypt the cloud data.

International Journal of Engineering Sciences & Research Technology, 2014

Cloud Computing has changed the phenomena of IT industry completely. It allows access to highly scalable, inexpensive, on demand computing resources that can execute the code and store data that are provided. But adoption and approach to cloud computing applies only if the security is ensured. Cloud computing is lacking in security, confidentiality and visibility. Secure the cloud means to secure the storage. Security is achieved by the encryption. There are various encryption standards to ensure the cloud security. Attribute-based encryption (ABE) is public key encryption technique that allows users to encrypt and decrypt messages based on user attributes. In a typical implementation, the size of the cipher text is proportional to the number of attributes associated with it and the decryption time is proportional to the number of attributes used during decryption. To reduce the decryption time in cloud outsourced decryption technique is used. By providing a transformation key to the cloud ABE cipher text is converted into simple cipher text and it only incurs a small computational overhead for the user to recover the plaintext from the transformed ciphertext.. To ensure that transformation performed by cloud server is correct and the data is not modified by the untrusted servers proposed system is introduced. This provides secured and Verifiable Outsourced decryption.

Multiagent and Grid Systems, 2019

Cloud data access control is a very important issue especially when data are outsourced into a third-party cloud server. Recently, some researchers are working to enhance the trust level of cloud users by developing the secured access control to store the data into a third-party server. CP-ABE (Ciphertext-Policy Attribute-Based Encryption) is a very fruitful technology for such situation providing a capability of encrypted data access control. The existing mechanisms for outsourced data access control are mostly centralized, where a single key distribution center works as attribute authority and generates attributes along with corresponding keys for all users. In some cases, multiple key distribution centers used to generate user attributes along with user secret keys to make the system decentralized. However, all such mechanisms are based on small universe CP-ABE, where attribute set need to define in the initial setup phase and therefore public parameters and ciphertext size are increased linearly with attribute numbers in the system. As the attribute numbers in an access control system in the cloud should not be defined initially or if new attribute required to add time to time in the system and the existing attribute may be required to revoke form the system, then small universe enabled CP-ABE is not scalable and efficient compared to large universe system. In a large universe system, initially the size of parameters is large but it makes the size of ciphertext short in the system. In the paper, we proposed an access control scheme using large universe CP-ABE with user revocation and to make more efficient using decryption computation outsourcing into the cloud. The proposed system helps efficiently decrypt the data using a lightweight device. We have analyzed the security, scalability, and performance of our proposed scheme with existing approaches with respect to communication and computation cost.

IJSRD, 2013

A distributed system is a collection of autonomous computers linked by a computer network that appear to the users of the system as a single computer. In a large distributed system, security is provided by the use of cryptographic techniques such as key generation. It has a major role in solving Computational problems. Data outsourcing in a distributed system represents that a data owner outsource the data to the service provider. Data outsourcing require flexible access control policies to enforce authorizing key policies and maintaining key generating policy updates are the important issues in distributed system. A new approach Cipher text policy attribute based encryption (CP-ABE) system is implemented for key generation, Cipher text is associated with an access structure, while the secret keys are labeled with a set of attributes. Therefore access control mechanism enforces security policies with efficient attribute and user revocation capabilities. CP-ABE provides a scalable way of encrypting data such that the encryptor defines the attribute set that the decryptor needs to possess in order to decrypt the cipher text. Further multiple service providers are used in a system and data is distributed among them. In CP-ABE fine grained access control can be achieved by dual encryption mechanism that is used to maintain the data. So computation overhead is reduced, it is used to securely manage the outsourced data.

Cloud 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. During the delegation, the cloud servers could tamper or replace the delegated cipher text and respond a forged computing result with malicious intent. Attribute-based encryption with delegation emerges. Since policy for general circuits enables to achieve the strongest form of access control, a construction for realizing circuit cipher text-policy attribute- based hybrid encryption with verifiable delegation has been considered in our work. A user is able to decrypt a cipher text if the key ’ s attribute set satisfies the access structure associated with a cipher text. CP-ABE under certain access policies. The users, who want to access the data files. They are most likely to outsource part of the decryption process to the cloud server. Designed the first ABE with outsourced decryption scheme to reduce the computation cost during decryption. Hybrid encryption with verifiable delegation. Confidentiality data should not be leaked even if malware or hackers infiltrate server. Verifiability the unauthorized user without enough attributes could not access data