FACOR is a new solution that enables flexible access control on outsourced data in mobile clouds using attribute-based encryption. It allows mobile users to outsource expensive encryption and decryption computations to proxies while only requiring full trust of attribute authorizations. FACOR also provides an outsourceable revocation process for mobile users to reduce the complexity of attribute-based revocations. The scheme achieves data security against collusion attacks and unauthorized access from revoked users.

1. FA COR: Flexible access control with outsourceable revocation in mobile
clouds
Abstract:
Access control is a key mechanism to secure outsourced data in mobile clouds.
Some existing solutions are proposed to enforce flexible access control on
outsourced data or reduce the computations performed by mobile devices.
However, less attention has been paid to the efficiency of revocation when there
are mobile devices needed to be revoked. In this paper, we put forward a new
solution, referred to as flexible access control with outsourceable revocation
(FACOR) for mobileclouds. The FACOR applies the attribute- based encryption to
enable flexible access control on outsourced data, and allows mobile users to
outsource the time-consuming encryption and decryption computations to
proxies, with only requiring attributes authorization to be fully trusted. As an
advantageous feature, FACOR provides an outsourceable revocation for mobile
users to reduce the complicated attribute-based revocation operations. The
security analysis shows that our FACOR scheme achieves data security against
collusion attacks and unauthorized accesses from revoked users. Both theoretical
and experimental results confirm that our proposed scheme greatly reliefs the
mobile devices from heavy encryption and decryption computations, as well as
the complicated revocation of access rights in mobile clouds.