Research On Quantum Signature Scheme Based On Five-particle Entangled State

As an important branch of cryptology,digital signature plays an immeasurable role in information security field.Due to unforgeability and non-repudiation,digital signature is widely applied in identity authentication and data integrity detection,such as e-commerce,e-voting and e-wallet.However,with the rapid development of technology and science,classical digital signature based on solving mathematical puzzles not only is threatened by super computer,but also suffers from unprecedent-ed crisis awareness in quantum computer.So,digital signature must find a safer design method before the arrival of quantum computer.Signature scheme designed by qubit is a new-type subject integrating quantum mechanics and classical signa-ture.Its unconditional secure in theory can be guaranteed by quantum mechanics characteristics.In the proposed quantum signature scheme,one of the most used resources is quantum entanglement state.With entanglement coherence of entanglement state,the secure and high-effcient signature scheme can be designed.This thesis will combine with the property of proxy signature and blind signature to design two quantum proxy blind signature schemes based on five-qubit entanglement state.Research achievements are shown as follows:1.To design a quantum proxy blind signature scheme based on genuine five-qubit entanglement state.First of all,message owners use the classical Vernam algorithm to blind messages,while signature participators share five-qubit entangle-ment state.Secondly,by performing quantum measurement on some random parti-cle,particle distribution eavesdrop-detection is finished.Finally,by using quantum teleportation principle,quantum measurement is used to finish proxy authoriza-tion,proxy signature and signature verification.Security analysis indicates that the scheme has unforgeability,non-repudiation and blindness and also can cancel proxy authorization.2.To design a quantum proxy blind signature scheme based on Bell state and tripartite GHZ state.The scheme uses quantum key distribution protocol to share secret key between signature participators.Message owners use keys to do bitwise xor operation for messages and to blind messages.Blind messages are coded into quantum messages by per 2-bits.The scheme regards the compound state of Bell state and tripartite GHZ state as a quantum channel,uses quantum teleportation to transfer principle of two-qubit state,and achieves proxy authorization,proxy sig-nature and signature verification through quantum measurement.Security analysis indicates that the scheme has unforgeability,non-repudiation and blindness and also can cancel proxy authorization.