Attribute-based Encryption is observed as a promising cryptographic leading tool to assurance data owners’ direct regulator over their data in public cloud storage. The former ABE schemes include only one authority to maintain the whole attribute set, which can carry a single-point bottleneck on both security and performance. Then, certain multi-authority schemes are planned, in which numerous authorities distinctly maintain split attribute subsets. However, the single-point bottleneck problem remains unsolved. In this survey paper, from another perspective, we conduct a threshold multi-authority CP-ABE access control scheme for public cloud storage, named TMACS, in which multiple authorities jointly manage a uniform attribute set. In TMACS, taking advantage of (t, n) threshold secret allocation, the master key can be shared among multiple authorities, and a lawful user can generate his/her secret key by interacting with any t authorities. Security and performance analysis results show that TMACS is not only verifiable secure when less than t authorities are compromised, but also robust when no less than t authorities are alive in the system. Also, by efficiently combining the traditional multi-authority scheme with TMACS, we construct a hybrid one, which satisfies the scenario of attributes coming from different authorities as well as achieving security and system-level robustness.