密码术,保密,和数据安全在公开和秘密部门中的机构都越来越依赖于电子数据处理。现在,有大量的数字数据聚集和存贮在大的计算机数据库中,并在用复杂的通讯网连在一起的计算机和终端设备之间进行传输。若没有适当的防护设施,这些数据在传输期间易被拦截(例如通过窃听),在存贮中也许会被通过物质手段调走或复制,这可能导致非人所愿地暴露数据,包括暗中侵犯其秘密。在传输和存贮数据时,数据还容易被越权删减,修改,或加进新的内容。还可能导致不正当地存取计算机资源和要求提供不正当的服务,或者导致伪造私人数据或商业记录,或进行欺骗勾当,包括增加 Cryptography, confidentiality, and data security Organizations in both public and private sectors are increasingly dependent on electronic data processing. Nowadays, a large amount of digital data is gathered and stored in a large computer database and transmitted between a computer and a terminal device connected together by a complicated communication network. In the absence of adequate protective equipment, these data can be easily intercepted (eg eavesdropped) during transit and may be diverted or duplicated through physical means in storage which may lead to inattention to data disclosure, including inadvertent encroachment Its secret. When transferring and storing data, the data can easily be overridden, modified, or added to new content. It may also result in improper access to computer resources and the demand to provide improper services, or to forge private data or business records, or to cheat activities, including to increase