public byte[] processInput(String theInput) {
        byte[] theOutput = null;

        if (state == WAITING_TO_SEND_DATA) {
        	theOutput = encryptedData;
            state = WAITING_FOR_CONFIRM_NUM;
        } else if (state == WAITING_FOR_CONFIRM_NUM) {
        	BuyerBackEnd.setConfirmNum(theInput);
        	BuyerBackEnd.setSuccessState(2);
        	theOutput = "Bye.".getBytes();
            state = WAITING_TO_SEND_DATA;
        }
        
        return theOutput;
    }