Analysis and improvement of Tian-Zhang-Li voting protocol based on controlled quantum teleportation

Recently Tian, Zhang and Li (TZL) have proposed a protocol for voting based on controlled quantum teleportation (Int. J. Theor. Phys. DOI 10.1007/s10773-015-2868-8). We have critically analyzed the protocol and have shown that it's neither efficient nor secure. Further, it is shown that in the TZL protocol, the scrutineer Charlie does not have the required control over the voting process. Apart from showing the limitations of TZL protocol, two improved protocols for quantum voting along the line of TZL protocol are proposed here. One of the proposed protocols is designed using a standard scheme of controlled deterministic secure quantum communication, and the other one is designed using the idea of quantum cryptographic switch which uses a technique known as permutation of particles (PoP). A few possible alternative approaches to accomplish the same task have also been discussed. Further, the efficiencies of the proposed protocols are reported, and it is shown that the proposed protocols are free from the limitations of the TZL protocol, and they are more efficient than the TZL protocol.