文件名称：Achieving Data Access Control in Cloud Computing
文件大小：269KB
文件格式：PDF
更新时间：2014-09-04 20:55:47
ABE, CPABE, CLOUD
Abstract—Cloud computing is an emerging computing paradigm in which resources of the computing infrastructure are provided as services over the Internet. Promising as it is, this paradigm also brings forth many new challenges for data security and access control when users outsource sensitive data for sharing on cloud servers, which are not within the same trust domain of data owners. To keep sensitive user data confidential from untrusted servers, existing work usually apply cryptographic methods by disclosing data decryption keys only to authorized users. However, in doing so, these solutions inevitably introduce heavy computation overhead on the data owner for key distribution and data management when fine-grained data access control is desired, and thus do not scale well. The problem of simultaneously achieving fine-grainedness, scalability, and data confidentiality of access control actually still remains unresolved. This paper addresses this challenging open issue by, on the one hand, defining and enforcing access policies based on data attributes, and, on the other hand, allowing the data owner to delegate most of the computation tasks involved in finegrained data access control to untrusted cloud servers without disclosing the underlying plaintexts. We achieve this goal by exploiting and uniquely combining techniques of attribute-based encryption (ABE), proxy re-encryption, and lazy re-encryption. Our proposed scheme also has salient properties of user access privilege confidentiality and user secret key accountability. Extensive analysis shows that our proposed scheme is highly efficient and provably secure under existing security models.