<PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.2" />

System.Configuration.ProtectedConfiguration

public static class ProtectedConfiguration
Provides access to the protected-configuration providers for the current application's configuration file.
namespace System.Configuration { public static class ProtectedConfiguration { public const string RsaProviderName = "RsaProtectedConfigurationProvider"; public const string DataProtectionProviderName = "DataProtectionConfigurationProvider"; public const string ProtectedDataSectionName = "configProtectedData"; public static ProtectedConfigurationProviderCollection Providers { get; } public static string DefaultProvider { get; } } }