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
