Quantum Blind Signature Protocol Design And Its Application In Privacy Protection Of Personal Credit Checking

Quantum computing is a new way of calculation in accordance with the theory of quantum mechanics, which can produce tremendous computing power. As an important branch of cryptography, the classical cryptography is being tested for the threat from the quantum computing.As an important branch of cryptography, digital signature is also confronted with severe security problems in the future quantum computing environment.This study aims at the quantum blind signature scheme, analyzes the particularity of quantum arbitration of blind signature, proposes a new classification of the quantum blind signature protocol, and points out that the quantum blind signature traceability problem relies on the trusted third party. Based on the discussion above, this research proposes four quantum blind signature schemes and two privacy preserving protocols. The main contributions of this dissertation are as follows:Quantum arbitrated asynchronous blind signature protocol: the existing quantum arbitration blind signature protocols usually adopt the workflow of "first blind next sign", and the discussion about the traceability of blind signature is almost ignored. A fair arbitrated quantum asynchronous blind signature protocol based on four particle GHZ state,which implements the work of sign and verify the blind signature by four roles. In addition, the traceability factor is added so that the signer can complete the tracking of the blind signature without the assistance of arbitration. This paper also proposes an asynchronous blind signature protocol based on quantum particle,the physical realization is simple, and restrictions on certain conditions in this agreement, blind signature can switch the order of operation and operation. Simultaneously, the safety about the arbitrated quantum signature are discussed in five aspects in terms of unforgeability, non-repudiation, blindness, verification and traceability.The arbitrated quantum synchronous blind signature protocol: The existing quantum arbitrated blind signature protocols are all asynchronous blind signature protocols. The blind operation and signature operation can be carried out at the same time in the two arbitrated quantum synchronous blind signature protocol proposed in this paper. The signer does not contact the coded plaintext (braille) particle sequence to simplify the blind operation and improve the efficiency and safety of the signature. In this paper, an arbitrated quantum synchronous blind signature protocol based on four particle Cluster state and a quantum synchronous blind signature protocol based on entanglement transition are proposed in the paper, the safety about the arbitrated synchronous quantum signature are discussed in five aspects in terms of unforgeability, non-repudiation, blindness,verification and traceability.It is concluded that on the basis of the discussion about the arbitrated quantum blind signature protocols and their security, the application of the blind signature is to be extend under the background of the specific application. The idea of privacy preserving protocol is indicated in this dissertation. And the study also puts forward two quantum privacy preserving protocols based on Bell states and a single particle, and discusses the similarities and differences about the privacy protection protocol, blind signature and confidential comparison.