A key approach to secure cloud computing is forthe data owner to store encrypted data in the cloud and issuedecryption keys to authorized users. Then when a user isrevoked the data owner will issue re-encryption commands tothe cloud to re-encrypt the data to prevent the revoked userfrom decrypting the data and to generate new decryption keys tovalid users so that they can continue to access the data. However since a cloud computing environment is comprised of many cloudservers such commands may not be received and executed by all of the cloud servers due to unreliable network communications. In this paper we solve this problem by proposing a timebased re-encryption scheme which enables thecloud servers to automatically re-encrypt data based on their internal clocks. Oursolution is built on top of a new encryption scheme attributebased encryption to allow fine-grain access control and does notrequire perfect clock synchronization for correctness
AES-BLOWFIDH
cloud computing
₹12000 (INR)
IEEE 2011