An Efficient KP-ABE with Short Ciphertexts in Prime OrderGroups under Standard Assumption

Abstract

We introduce an efficient Key-Policy Attribute-Based Encryption (KP-ABE) scheme in prime order groups. Our scheme is semi-adaptively secure under the decisional linear assumption and supports a large universe of attributes and multi-use of attributes. Those properties are critical for real applications of KP-ABE schemes since they enable an efficient and flexible access control. Prior to our work, existing KP-ABE schemes with short ciphertexts were in composite order groups or utilized either Dual Pairing Vector Spaces (DPVS) or Dual System Groups (DSG) in prime order groups. However, those techniques brought an efficiency loss. In this work, we utilize a nested dual system encryption which is a variant of Waters' dual system encryption (Crypto' 09) to achieve semi-adaptively secure KP-ABE. As a result, we obtain a new scheme having better efficiency compared to existing schemes while it keeps a semi-adaptive security under the standard assumption. We implement our scheme and compare its efficiency with the previous best work.