To keep the data in the cloud confidential against unauthorized parties, a cryptographic access control solution called hybrid cloud re-encryption (HCRE) based on attribute-based encryption (ABE) was introduced. HCRE designed a secret sharing scheme to delegate the task of ABE re-encryption to the cloud service provider (CSP), which alleviates the administering burdens on the data owner. Experiments show that HCRE can handle dynamic access policies in a more efficient way. Additionally, HCRE does not reveal extra information of the plaintext to the CSP, thus it does no harm to the data confidentiality.
Hong Cheng,Zhang Min,Feng Deng-Guo. achieving efficient dynamic cryptographic access control in cloud storage[J]. Tongxin Xuebao/Journal on Communications,2011-01-01,32(7):125-132.