public static void Decrypt(string token, out string username, out string password)
    {
        var usernameAndPass = ApiRSA.Decrypt(token).Split(/*split username and password*/);

        username = usernameAndPass[0];
        password = usernameAndPass[1];
    }
 public static string Encrypt(string username, string password)
 {
     return(ApiRSA.Encrypt(/*join username and password*/));
 }