摘要
Attribute revocation is inevitable and al- so important for Attribute-Based Encryption （ABE） in practice. However, little attention has been paid to this issue, and it retrains one of the rmin obsta-cles for the application of ABE. Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the users＇ private keys will be affected when the revo-cation events occur. Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the users＇ private keys will be affected by revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or they can only be proven to be selectively secure. In this paper, we first define a model of adaptively secure ABE supporting the at- tribute revocation under direct revocation model. Then we propose a Key-Policy ABE （KP-ABE） scheme and a Ciphertext-Policy ABE （CP-ABE） scheme on composite order bilinear groups. Finally, we prove our schemes to be adaptively secure by employing the methodology of dual system eno cryption.
Attribute revocation is inevitable and also important for Attribute-Based Encryption (ABE) in practice.However,little attention has been paid to this issue,and it remains one of the main obstacles for the application of ABE.Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the users' private keys will be affected when the revocation events occur.Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the users' private keys will be affected by revocation,they mostly focused on the user revocation that revokes the user's whole attributes,or they can only be proven to be selectively secure.In this paper,we first define a model of adaptively secure ABE supporting the attribute revocation under direct revocation model.Then we propose a Key-Policy ABE (KP-ABE) scheme and a Ciphertext-Policy ABE (CP-ABE) scheme on composite order bilinear groups.Finally,we prove our schemes to be adaptively secure by employing the methodology of dual system encryption.
