  The distributed denial of service (DDoS) attack is detrimental to businesses
and individuals as people are heavily relying on the Internet. Due to
remarkable profits, crackers favor DDoS as cybersecurity weapons to attack a
victim. Even worse, edge servers are more vulnerable. Current solutions lack
adequate consideration to the expense of attackers and inter-defender
collaborations. Hence, we revisit the DDoS attack and defense, clarifying the
advantages and disadvantages of both parties. We further propose a joint
defense framework to defeat attackers by incurring a significant increment of
required bots and enlarging attack expenses. The quantitative evaluation and
experimental assessment showcase that such expense can surge up to thousands of
times. The skyrocket of expenses leads to heavy loss to the cracker, which
prevents further attacks.
