A Distributed Approach to Defend Web Service from DDoS Attacks

Most of the business applications on the Internet are dependent on web services for theirtransactions. Distributed denial of service (DDoS) attacks either degrade or completely disruptweb services by sending flood of packets and requests towards the victim web servers. An arrayof defense schemes are proposed but still defending web service from DDoS attacks is largely anunsolvable problem so far. In this paper, DDoS defense schemes are classified into centralizedand distributed and their relative advantages and disadvantages are explored. An ISP baseddistributed approach is a pragmatic solution to defend from DDoS attacks due to its autonomouscontrol, more resources, and incremental scope. Traffic cluster entropy is conceptualized fromsource address entropy and the combination is used to detect various types of DDoS attacksagainst the web service. A framework is proposed which can detect the attack, characterizeattack sources, and filter the attack packets as early as possible so as to minimize the collateraldamage