Base64 Helpers

public static string ToBase64(this string input)
{
 if(string.IsNullOrEmpty(input)) return input;

 return Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(input));
}

public static string FromBase64(this string input)
{
 if(string.IsNullOrEmpty(input)) return input;

 return System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(input));
}

Use:

var a = "input";
var b = a.ToBase64();
var c = b.FromBase64();