Ciphertext policy attribute-based encryption from lattices

Abstract

Sahai and Waters [6] proposed Attribute-Based Encryption (ABE) as a new paradigm of encryption algorithms that allow the sender to set a policy describing who can decrypt a particular ciphertext. In this paper, we first propose a ciphertext policy attribute-based encryption (CP-ABE) scheme from lattices, which supports flexible threshold access policies on literal (or boolean) attributes. Then we extend it to support multi-valued attributes without increasing the public key and ciphertext size. Our scheme's master secret key has only one matrix despite of the number of the system's attributes. The security of our schemes is based on the worst-case hardness on lattices.