%0 Journal Article %A Xixi Yan %A Hao Ni %A Yuan Liu %A Dezhi Han %T Privacy-preserving Multi-authority Attribute-based Encryption with Dynamic Policy Updating in PHR %J Computer Science and Information Systems %D 2019 %V 16 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/CSIS_2019_16_3_a8/ %F CSIS_2019_16_3_a8