Evaluation Model of Cloud Storage Security Level with the Fusion Analytic Hierarchy Process

In view of excessive calculation and bandwidth cost, excessive complexity of the user access permission revocation in the cloud storage service, taking the ciphertext access control scheme of property encryption system (CP - ABE) of ciphertext strategy as the theoretical background, this article designed a cloud storage permission revocation optimization mechanism based on the dynamic re-encryption, namely DRPRO. The mechanism uses (k, n) threshold scheme to divide data information into several blocks, and dynamically selects a data information block to implement the re-encryption, and completes the user access permission revocation realization process by data partitioning, reconstruction, transfer, extraction, permission revocation and other subalgorithm successively. Theoretical analysis and simulation experiment evaluation show that under the premise of ensuring the high security of cloud storage service user data, DRPRO mechanism reduces the calculation and bandwidth cost of the user access permission revocation effectively, and its performance efficiency has been further optimized and improved.