With the development of information technology in some areas, industries, units, the supporting security is relatively lagging behind applying modern communications and office technology, it causes more security leaks and loopholes, and some units even in a defenseless state. There are serious security documents hidden. This article ensures overall security of documents transmission process, uses data encryption, digital signatures, digital envelopes to identity authentication, authorization, encryption, signatures, audit based on PKI. It helps speed up the pace of information processing, enhances informationprocessing capacity, enhances quality and services level of party and government organs at all levels, so as to better prefectural economic construction and social development.