internal static string ComputeEncodedMD5FromEncodedString(string base64EncodedString)
{
var unencodedValue = Convert.FromBase64String(base64EncodedString);
var valueMD5 = CryptoUtilFactory.CryptoInstance.ComputeMD5Hash(unencodedValue);
var encodedMD5 = Convert.ToBase64String(valueMD5);
return encodedMD5;
}