Critique of Some Fine-Grained Access Control Models in Cloud Computing Environment

Abstract

Cloud computing is an emerging computing tool in which resources accessed as a service over Internet on pay for use basis. Most of the service providers are changing their server storage to cloud storage. It is a great challenge for the service provider to attract the customers to store their sensitive data/file in the cloud storage. Service provisioning with respect to privacy preservation and data security is an area of concern. In general the cloud servers are being deployed on different trusted domain by different data owner. There will be need to encrypt sensitive data and store them in cloud server and disclose decryption key to authorized users. But drawback of this method is that owner of file can selectively share data by sharing his private key. Most of the computation for key distribution and management are done by the data owner. T here are various fine-grained access control models for sharing of encrypted data on cloud server. Some of these model used key policy Attribute Based Encryption (KP-ABE) and others used Cipher text Policy Attribute Based Encryption (CP-ABE). These techniques can be used to keep shared data confidential even if data is stored on remote server. These models are used to define and enforcing access control policy based on attributes and delegates most of the computation task involved in fine grained access control without disclosing data to storage server. This paper under takes critical study on available access control approaches that has been deployed in cloud computing environment.