本文件规定了CMS数字签名和CAdES数字签名中定义的元素，这些元素能够长时间验证数字签名。 它没有给出关于数字签名本身的新技术规范，也没有对已经存在的关于数字签名的技术规范的使用提出新的限制。 注意CAdES数字签名是密码消息语法（CMS）的扩展规范，应用广泛。

This document specifies the elements, among those defined in CMS digital signatures and CAdES digital signatures that enable verification of a digital signature over a long period of time. It does not give new technical specifications about the digital signature itself, nor new restrictions of usage of the technical specifications about the digital signatures which have already existed. NOTE？CAdES digital signature is the extended specification of Cryptographic message syntax (CMS), used widely.