A Survey on Panda: Public Auditing for Shared Data with Efficient User Revocation in the Cloud

Abstract — In today's Computing world Cloud computing is one of the biggest innovation which uses advanced computational power and it improves data sharing and data storing capabilities. Main difficulty in cloud computing was issues of data integrity, data privacy and data access by unauthorised users. TTA (Trusted Third Party) is used to store and share data in cloud computing. Modification and sharing of data is quite simple as a group. To verify integrity of the shared data, members in the group needs to compute signatures on all shared data 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 threats in data sharing in groups. During user revocation shared data block signed by revoked user needs to download and re-sign by existing user. This task is very inefficacious due to the large size of shared data blocks on cloud. PANDA Plus is the new public auditing mechanism for the maintaining integrity of shared data with efficient user revocation in the cloud. This mechanism is based on proxy re-signatures concept which allows the cloud to re-sign blocks on behalf of existing users during user revocation, so that downloading of shared data blocks is not required. PANDA Plus is the public auditor which audits the integrity of shared data without retrieving the entire data from the cloud. It also monitor batch to verify multiple auditing tasks simultaneously