No abstract

In a traditional ciphertext-policy attribute-based encryption (CP-ABE) scheme, an access structure, also refereed to as ciphertext-policy, is sent along with a ciphertext explicitly, and anyone who obtains a ciphertext can know the access structure associated with the ciphertext. In certain applications, access structures contain sensitive information and must be protected from everyone except the users whose private key attributes satisfy the access structures.In this paper, we first propose a new model for CP-ABE with partially hidden access structures. In our model, each attribute consists of two parts: an attribute name and its value; if the private key attributes of a user do not satisfy the access structure associated with a ciphertext, the specific attribute values of the access structure are hidden, while other information about the access structure is public.Based on the CP-ABE scheme proposed by Lewko et al. [14] recently, we then present an efficient construction of CP-ABE with partially hidden access structures. Compared to previous works in this field, our construction is more flexible and expressive and is proven fully secure in the standard model.

No abstract

No abstract

No abstract