Key-Policy Weighted Attribute based Encryption for fine-grained access control

When we step into the new internet era, large numbers of new techniques have emerged in order to make our life better. However, these new techniques require some new properties in order to keep personal information confidentially which the traditional encryption method cannot catch up with. Recently, a new encryption primitive called Attribute Based Encryption(ABE) have appeared because it can achieve both information security and fine-grained access control. Although the ABE scheme has these new characters which can keep the information security that can fit for the new widely used technique, nevertheless, the characteristic of attributes are treated in the identical level in most of traditional schemes. In the real scenario, the importance of each attributes is always different. In this paper, we propose a scheme called Key-Policy Weighted Attribute based Encryption (KP-WABE) while the attributes have different weights according to their importance in the system. The KP-WABE scheme is proved to be secure under the l-th Bilinear Diffie-Hellman Inversion Assumption. Our scheme can be considered as the generalization of traditional KP-ABE scheme when all attributes have equal weights.