如何在.net Framework4.5中使用System.Configuration.DpapiProtectedConfigurationProvider版本2？

<configProtectedData>
  <providers>
    <add name="DpapiProtectedConfigurationProvider"
         type="System.Configuration.DpapiProtectedConfigurationProvider, System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
         description="Uses the Windows Data Protection API (DPAPI) to encrypt and decrypt."
         keyContainerName="MyKeyContainer" />
  </providers>
</configProtectedData>

using System.Configuration;

// 加密配置节
Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
ConfigurationSection section = config.GetSection("sectionName");
if (section != null && !section.SectionInformation.IsProtected)
{
    section.SectionInformation.ProtectSection("DpapiProtectedConfigurationProvider");
    config.Save();
}

// 解密配置节
Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
ConfigurationSection section = config.GetSection("sectionName");
if (section != null && section.SectionInformation.IsProtected)
{
    section.SectionInformation.UnprotectSection();
    config.Save();
}