New Proof Techniques for DLIN-Based Adaptively Secure Attribute-Based Encryption and Their Application.
Katsuyuki Takashima · 2015
Abstract. We propose adaptively secure attribute-based encryption (ABE) schemes for boolean formulas over large universe attributes from the de-cisional linear (DLIN) assumption, which allow an arbitrary number of attribute reuse in an available formula without the previously employed redundant multiple encoding technique. Based on the key-policy (KP-)ABE scheme, we have an adaptively secure communication-efficient non-interactive verifiable computation (NI-VC) from DLIN. While any previ-ous adaptive NI-VC from a static assumption has multiplicatively depen-dent communication cost on the input variable multiplicity, we remove the dependency. For achieving the results, we develop a new encoding method for access policy matrix for ABE, by decoupling linear secret sharing (LSS) into its matrix and randomness, and partially randomiz-ing the LSS shares in simulation. The new techniques are of independent interest and we expect it will find another application than ABE.