AbstractPreferences equivalent in C#

Is there any class or analog for work with Base64 in c# like Abs开发者_如何学PythontractPreferences in java?

Convert.ToBase64String http://msdn.microsoft.com/en-us/library/system.convert.tobase64string.aspx
Convert.FromBase64String http://msdn.microsoft.com/en-us/library/system.convert.frombase64string.aspx