Signature Schemes And Voting Protocol Based On The Quantum Controlled Teleportation

Digital signature, as one of the most important components of modern cryp-tography, has been widely used in electronic commerce, electronic voting, testamen-t distribution and other related fields. With the rapid development of quantum technology and quantum computer, the classical signature schemes become unsafe, and more and more researchers pay more attention to quantum signature schemes. Comparing with the traditional cryptography, quantum cryptography satisfies un-conditional security, and it can resist against eavesdropping attack, which has an important development prospect and a great research significance. This thesis is devoted to quantum signature schemes and voting protocol based on the controlled teleportation with the following aspects:1. We have researched a quantum multi-proxy blind signature scheme. Multi-proxy blind signature scheme requires an original signer to delegate a group of proxy signers to finish the scheme, and the proxy signers do not know the concrete content of the message so as to avoid the exposure of the sensitive message. In our thesis, a quantum multi-proxy blind signature scheme is proposed based on the controlled teleportation. Different from classical signature scheme, the security of our scheme is guaranteed by the quantum one-time pad and quantum key distribution. Ad-ditionally, the scheme is proposed based on the genuine four-qubit entangled state which saves resource comparing with other schemes, and the analysis shows that our scheme satisfies the security features of unconditional security, unforgeability and blindness.2. We have researched two quantum proxy multi-signature schemes based on eight-qubit entangled state, which require some original signers to delegate one proxy signer. Furthermore, considering the hierarchical physical structure of eight-qubit entangled state, the second scheme only needs three parties from all the six original signers to generate a proxy signature during the signing phase, which has a wide application and a high efficiency.3. We have researched the quantum voting protocol based on genuine four-qubit entangled state. After authenticating voters' quantum identity with zero-knowledge proof provided by the notary organization CA, the eligible voter's quantum operation which represents his vote information can be transmitted to the tallyman successfully with the supervision of Charlie.