Biblio
With the rising popularity of file-sharing services such as Google Drive and Dropbox in the workflows of individuals and corporations alike, the protection of client-outsourced data from unauthorized access or tampering remains a major security concern. Existing cryptographic solutions to this problem typically require server-side support, involve non-trivial key management on the part of users, and suffer from severe re-encryption penalties upon access revocations. This combination of performance overheads and management burdens makes this class of solutions undesirable in situations where performant, platform-agnostic, dynamic sharing of user content is required. We present NEXUS, a stackable filesystem that leverages trusted hardware to provide confidentiality and integrity for user files stored on untrusted platforms. NEXUS is explicitly designed to balance security, portability, and performance: it supports dynamic sharing of protected volumes on any platform exposing a file access API without requiring server-side support, enables the use of fine-grained access control policies to allow for selective sharing, and avoids the key revocation and file re-encryption overheads associated with other cryptographic approaches to access control. This combination of features is made possible by the use of a client-side Intel SGX enclave that is used to protect and share NEXUS volumes, ensuring that cryptographic keys never leave enclave memory and obviating the need to reencrypt files upon revocation of access rights. We implemented a NEXUS prototype that runs on top of the AFS filesystem and show that it incurs ×2 overhead for a variety of common file and database operations.
Cloud computing is an application and set of services given through the internet. However it is an emerging technology for shared infrastructure but it lacks with an access rights and security mechanism. As it lacks security issues for the cloud users our system focuses only on the security provided through the token management system. It is based on the internet where computing is done through the virtual shared servers for providing infrastructure, software, platform and security as a services. In which security plays an important role in the cloud service. Hence, this security has been given with three types of services such as mutual authentication, directory services, token granting for the resources. Since, existing token issuing mechanism does not provide scalability to large data sets and also increases memory overhead between the client and the server. Hence, our proposed work focuses on providing tokens to the users, which addresses the problem of scalability and memory overhead. The proposed framework of token management system monitors the entire operations of the cloud and there by managing the entire cloud infrastructure. Our model comes under the new category of cloud model known as "Security as a Service". This paper provides the security framework as an architectural model to verify user authorization and data correctness of the resource stored thereby provides guarantee to the data owner for their resource stored into the cloud This framework also describes about the storage of token in a secured manner and it also facilitates search and usage of tokens for auditing purpose and supervision of the users.