ensure public security
3.Article 47 After the occurrence of flood and waterlogging，the relevant people's government should organize the relevant departments and units to ensure the relief work in the disaster area in respect of supply of necessities health care and immunity，supply of relief materials，public security，resumption of classes，resumption of production and rebuilding of homes as well as repairing of various engineering structures destroyed in floodwater within its jurisdiction.
7.To ensure the Internet security, the authors have achieved the realization of the Public Key Infras-tructure(PKI) which is used popularly in the world. In the realization of PKI, using authentication service of integrality, it can not only provide the entity authentication, but also protect the integrality of signature. By using a digital envelop, it provides service of the PKI security.
