Dynamic ciphertext-policy attribute-based encryption for expressive access policy

Abstract

In this paper, we address the problem of key update for attribute level dynamic operations in ciphertext-policy attribute-based encryption (CP-ABE). We present an efficient CP-ABE construction which features attribute addition to users with no cost and an attribute updation functionality at a cost proportional to ω, where ω is the maximum number of users hold each attribute. The proposed CP-ABE scheme resists collusion attacks, secure against chosen plaintext attacks in the generic bilinear group model, and work for any monotone access policy represented in a tree wherein internal nodes are threshold gates and leaf nodes are associated with attributes. © 2014 Springer International Publishing Switzerland.