adhar image mask

static void Main(string[] args)
{
    string  cardNumber = "345612343456";
    var cardNumber1 = string.Format("########{0}", cardNumber.Substring(8, 4));
    var maskedCardNumberWithSpaces = Regex.Replace(cardNumber1, ".{4}", "$0 ");
    Console.WriteLine(maskedCardNumberWithSpaces);
    Console.Read();
}

when uploading a adhar card, at that time first 8 character of adhaar no is masked and then save.

when bind in grid view then image is displayed with mask adhaar no

You need to provide an explanation for the content and what you have accomplished so far.