Protect/Encrypt config file in c#

Assume that we have web.config or app.config file like this:

XML:

<?xml version="1.0" encoding="utf-8"?>
>
>
name="AdventureData" connectionString="adventuredb"
providerName="System.Data.SqlClient" />
>
>
key="UserName" value="Vijay" />
key="password" value="dhiraj" />
key="dbIP" value="dbAdventure"/>
>
>

example :- ProtectSection("appSettings","DataProtectionConfigurationProvider");

private void ProtectSection(string sectionName,
                                  string provider) {     Configuration config =         WebConfigurationManager.             OpenWebConfiguration(Request.ApplicationPath);      ConfigurationSection section =
                config.GetSection(sectionName);      if (section != null &&
             !section.SectionInformation.IsProtected)     {         section.SectionInformation.ProtectSection(provider);         config.Save();     } }

private void UnProtectSection(string sectionName) {     Configuration config =         WebConfigurationManager.             OpenWebConfiguration(Request.ApplicationPath);      ConfigurationSection section =
             config.GetSection(sectionName);      if (section != null &&
         section.SectionInformation.IsProtected)     {         section.SectionInformation.UnprotectSection();         config.Save();     } }