关键词: 网络安全, 低速率拒绝服务攻击, TCP拥塞控制, AQM, 攻击防范

Abstract: Low-rate denial-of-service attack is a novel category of attacks that are aimed at exploiting the adaptive behavior exhibited by several network and system protocols. Different from traditional DoS attacks， this kind of attacks can make serious destroy on the victims by using periodically non-suspicious low-rate attack streams. Since they have been brought forward， these new attacks have caused special concern； the problems of detecting and defending towards them have gradually become important research issues in the network security area. In the paper， theoretical analyses， modeling and simulations of various LDoS attacks are presented， the difficulties of defending and current solutions are discussed. At the end of the paper， several problems which need further researches are put forward， in order to provide reference to the future research work on the defending of this kind of attacks.

Key words: network security, Low-rate DoS （LDoS） attacks, TCP congestion control, AQM, attack defense