Access control mechanisms for outsourced data in cloud

Cloud Computing poses new security and access control challenges as the users outsource their sensitive data onto cloud storage. The outsourced data should be protected from unauthorized users access including the honest-but-curious cloud servers those hosts the data. In this paper, we propose two access control mechanisms based on (1) Polynomial interpolation technique and (2) Multilinear map. In these schemes, the authorized user need to store only a single key material irrespective of number of data items to which he has authorized access.