With the development of information technology,E-commerce has appeared and gained its great advantage over traditional business. And the facility of such kind of business as E-payment and E-transaction has embodied E-commerce'great impact on our life.But because Internet is an open system, great importance has been attached to the security problem.If security area has problems,E-commerce will be hurt severely.This paper analysed several important issues to be resolved in E-commerce and introduced a solution...