CMS is used to digitally sign or encrypt arbitrary messages. CMS describes an encapsulation syntax for data protection. It supports digital signatures and Encryption. The syntax allows multiple encapsulation, so one encapsulation envelope can be nested inside another. Likewise, one party can digitally sign some previously encapsulated data. It also allows arbitrary attributes, such as signing time, to be authenticated along with the message content, and provides for other attributes such as counter-signatures to be associated with a signature.
　　CMS被用于数据签名或者任意消息加密中。CMS提供了一套用于数据保护的数据封装语法。该语法支持数据签名和数据加密。该语法允许多重封装，所以一封数据信封能被另外一封数据信封所封装。同样的，该语法封装数据的部分数据位可以用来表示被封装数据。也允附加一些属性如签名时间，它和内容信息一起用于鉴别信息;计数器属性，它为其它属性提供计数信息。考试大(www．Examda。com)