Design And Research On Quantum Digital Signature Scheme

Digital signature is an important topic in modern cryptography and it is one of the core technologies of information security. Digital signature is a digital simulation of handwritten signature in the real life. It guarantees the authenticity, integrity and non-repudiation of electronic information and realizes authentication. As well known to all, classical digital signature scheme mainly relies on a variety of mathematical puzzle issues to provide security protection. However, with the continuous improvement of computing power, these classical schemes are vulnerable to break. On the other hand, quantum digital signature scheme, which combines quantum cryptography with digital signature techniques,can achieve unconditional security by using the physical principles of quantum theory. It will be widely used in the field of e-commerce, e-government and so on.In the quantum digital signature, we study the quantum digital signature schemes under two application scenarios. The details are as follows.Firstly, we design an improved quantum broadcasting multiple blind signature scheme. The security of Tian el al.’s quantum broadcasting multiple blind signature scheme based on quantum teleportation is analyzed. It does not satisfy some properties of blind signature, such as blindness, unforgeability and irreversibility. In order to overcome these security problems, we modify it. The improvements include the use of four non-orthogonal states in two mutually unbiased bases to blind information, the preparation of EPR particles by signer Ui instead of Alice and the use of a new quantum one-time pad algorithm to encrypt quantum states. Compared to the original scheme, the security of the modified scheme is greatly improved.Secondly, a quantum anonymous veto scheme based on orbital angular momentum states of a photon is proposed. In the scheme, with the operation of orbital angular momentum states of a single photon, the number of vetoes can be obtained. Compared to Rahaman et al.’s quantum anonymous veto scheme base on GHZ states, our scheme can well protect the anonymity of members and can get the exact number of vetoes. In addition,there is no limit to the number of participants for the current experimental techniques.