研究成果

Attribute-based encryption with equality test (ABEET) is an extension of the ordinary attribute-based encryption (ABE), where trapdoors enable us to check whether two ciphertexts are encryptions of the same message. Thus far, several CCA-secure ABEET schemes have been proposed for monotone span programs satisfying selective security under q-type assumptions. In this paper, we propose a generic construction of CCA-secure ABEET from delegatable ABE. Specifically, our construction is an attribute-based extension of Lee et al.'s generic construction of identity-based encryption with equality test from hierarchical identity-based encryption. Even as far as we know, there are various delegatable ABE schemes. Therefore, we obtain various ABEET schemes with new properties that have not been achieved before such as various predicates, adaptive security, standard assumptions, compact ciphertexts/secret keys, and lattice-based constructions.