The Use of Dynamic Sliding Window with IPSec


IPSec (IP security) technology is used to protect the local computer networks and the internet from attacks. The most illustrious attacks against networks are the replay attacks where IPSec technology introduces a solution called sliding window through which the packets will be protected. This window involves packets each has a distinct sequence number. This sequence number prevents replay attacks. But, there is a problem related to this solution: when the packet is received late it will be discarded whether it was good or forged. This usually causes a big losses in the good packets. In this paper, the researcher discusses the use of the dynamic sliding window which is a window added to the original one. This window keeps most of the good packets that have been discarded (reorder packets) and which comes before the original window. The dynamic window moves automatically with the original window. This dynamic window makes the modified protocol introduce the best solution which is more efficient than the original protocol since it keeps a large set of good reorder packets. It has been found that the dynamic window saves more than %85 of the reorder packets.