A Novel Approach for Efficient User Revocation with Maintaining Shared Data Integrity on Cloud

Cloud computing is the biggest innovation in computing world. It provides great facilities of data sharing and data storing to its users. Here a main risk occurs as data security in aspects of data integrity, data privacy and data access by unauthorized users. TTA (Trusted Third Party) is used by cloud service providers to ensure data security and privacy. In cloud, data modification and data sharing among the group of users is very simple task .To maintain integrity of the shared data,group members needs to compute signatures on all shared data which are available in blocks. Different blocks in shared data are generally signed by different users due to data modifications performed by different users. User revocation is one of the biggest security issue during data sharing. After user revocation, shared data signed by revoked user, needs to re-sign by existing user.This task is very inefficacious due to the large size of shared data needs to download before re-signing it. This paper is a detail description of cloud public auditor which is used for the maintaining integrity of shared data with efficient user revocation in the cloud. This mechanism uses concept of proxy re-signatures which allows the cloud to re-sign blocks on behalf of existing users during user revocation, so there is no need of data downloading. It also performs batch monitoring to verify multiple tasks simultaneously. DOI: 10.17762/ijritcc2321-8169.150612

A-MAKE: an efficient, anonymous and accountable authentication framework for WMNs

In this paper, we propose a framework, named as A-MAKE, which efficiently provides security, privacy, and accountability for communications in wireless mesh networks. More specifically, the framework provides an anonymous mutual authentication protocol whereby legitimate users can connect to network from anywhere without being identified or tracked. No single party (e.g., network operator) can violate the privacy of a user, which is provided in our framework in the strongest sense. Our framework utilizes group signatures, where the private key and the credentials of the users are generated through a secure three-party protocol. User accountability is implemented via user revocation protocol that can be executed by two semitrusted authorities, one of which is the network operator. The assumptions about the trust level of the network operator are relaxed. Our framework makes use of much more efficient signature generation and verification algorithms in terms of computation complexity than their counterparts in literature, where signature size is comparable to the shortest signatures proposed for similar purposes so far

Data Sharing Securely for Administrators of Dynamic Groups in Cloud

In recent year’s cloud computing is popularly increased day by day in the form of securing, updating, storing, sharing confidential data. Today’s condition about data security in cloud computing is very bad thing happens when people work on cloud for confidential company data. System provides scheme for secured data sharing when we use dynamic groups in an un-trusted clouds. In a system, users can share data in other groups without revealing identity privacy to the cloud. Efficient user revocation and new user joining is also supported by the system. Public revocation list is used for efficient user revocation without updating the private keys of the other users. New users before participation can decrypt directly. User within a group is identified by a group signature. Also public revocation list is used. System is a secure data sharing scheme in a multiple group policy. DOI: 10.17762/ijritcc2321-8169.15014

Attribute-Based Encryption Optimized for Cloud Computing

Abstract. In this work, we aim to make attribute-based encryption (ABE) more suitable for access control to data stored in the cloud. For this purpose, we concentrate on giving to the encryptor full control over the access rights, providing feasible key management even in case of multiple independent authorities, and enabling viable user revocation, which is essential in practice. Our main result is an extension of the decentralized CP-ABE scheme of Lewko and Waters [LW11] with identity-based user revocation. Our revocation system is made feasible by removing the computational burden of a revocation event from the cloud service provider, at the expense of some permanent, yet acceptable overhead of the encryption and decryption algorithms run by the users. Thus, the computation overhead is distributed over a potentially large number of users, instead of putting it on a single party (e.g., a proxy server), which would easily lead to a performance bottleneck. Besides describing our scheme, we also give a formal proof of its security in the generic bilinear group and random oracle models.

GROUP USER REVOCATION AND INTEGRITY AUDITING OF SHARED DATA IN CLOUD ENVIRONMENT

The advent of the cloud computing makes storage outsourcing becomes a rising trend, which promotes the secure remote data auditing a hot topic that appeared in the research literature. Recently some researches consider the problem of secure and efficient public data integrity auditing for shared dynamic data. In this paper, signifies that the collusion attack in the exiting scheme and provide an efficient public integrity auditing scheme with secure group user revocation based on vector commitment and verifier-local revocation group signature. Analysis shows a concrete scheme based on the scheme definition. The scheme supports the public checking and efficient user revocation and also some nice properties, such as confidently, efficiency, count ability and traceability of secure group user revocation

Revocable Key-Aggregate Cryptosystem for Data Sharing in Cloud

With the rapid development of network and storage technology, cloud storage has become a new service mode, while data sharing and user revocation are important functions in the cloud storage. Therefore, according to the characteristics of cloud storage, a revocable key-aggregate encryption scheme is put forward based on subset-cover framework. The proposed scheme not only has the key-aggregate characteristics, which greatly simplifies the user’s key management, but also can revoke user access permissions, realizing the flexible and effective access control. When user revocation occurs, it allows cloud server to update the ciphertext so that revoked users can not have access to the new ciphertext, while nonrevoked users do not need to update their private keys. In addition, a verification mechanism is provided in the proposed scheme, which can verify the updated ciphertext and ensure that the user revocation is performed correctly. Compared with the existing schemes, this scheme can not only reduce the cost of key management and storage, but also realize user revocation and achieve user’s access control efficiently. Finally, the proposed scheme can be proved to be selective chosen-plaintext security in the standard model