| In recent years, information technology is developing in a very high speed. It is promoting the information society towards a more advanced stage in a revolutionary way. Currently and in the future, information will be a kind of resource, which is more precious than oi. So almost all the countries in the world are constructing and competing for that kind of resource. Information is playing an important role in the field of military, government, health care, finance, e-commerce and e-government. Therefore the safety problem in the field of information has become increasingly prominent, and it is attracting more and more people’s attention. Especially those information involving personal privacy, such as the electronic medical records of patients, and personal electronic files, the registration information of people, personal account information, etc. So these information are very likely to be intercepted, eavesdropped disclosed and counterfeited when they are stored in a personal computer or needed to be transported by the Internet.Digital signature is the core technology of information security. It provides a series of services for information security, for example, it can can offer a kind of service that is authenticated, integrated and non-repudiated in the process of information transmission. With the popularization of network, the purpose of proposing digital signatures is to replace the manual signature and seal in people’s daily life, which promoted the development of information networks greatly. Digital signatures is playing a role in escorting the transmission of information, and it is widely used in fields which calls for high information security, such as e-commerce, e-government, e-voting.Traditional digital signature is managed by the digital certificate and its core is digital Certificate Authority(Certificate Authority). So there’s no doubt that it exists problems like certificate store, certificate management and certificate hosting, which will lead to high system cost and the complexity of management. Problems will promote development. We put forward the identity based digital signature in order to solve this problem, which is is a hot research topic in the field of cryptography in recent years.Based on the study of the basic knowledge of cryptography and the latest research results of identity based encryption system abroad, the writer has done the following work:(1) Study the theoretical basis related to number theory, and analyzed the identity-based encryption cryptosystem in depth. The writer gives identity-based cryptographic system running processes and schematics, and the results of the analysis are given based on PKI public key cryptography and a detailed comparison and analysis.(2) Learned the basic principle of digital signature, analyzed the related technology of digital signature. The writer has carried on the discussion to the application of digital signature in e-government system, and used digital signature technology to improve an existing electronic voting system in a university and gives an improved flow.(3) Analyzed and summarized the existing identity based digital signature scheme and pointed out the scheme that can be improved. The writer constructed a new digital signature scheme based on identity, analyzed and proved its security. Finally, analyzed and summarized the efficiency of the new scheme,and given the summarized results and time-consuming simulation results. |
