Book123

    Free register and download UseNet downloader, then you can FREE Download from UseNet.

    Download without Limit " Free PDF: Models of Active Worm Defenses " from UseNet for FREE!

Models of Active Worm Defenses DavidM. Nicol Michael Liljenstam Coordinated Science & 8230; may have inhibited consideration for general use in the Internet. However, active defense may & 8230; To date most techniques proposed are passive, in-so-far as they attempt to block or slow a worm, or detect and filter it. Active defenses take the battle to the worm—trying to eliminate or isolate in- fectedhosts, and/or automatically and actively patch sus- ceptiblebutas-yet-uninfected hosts, without the knowledge of the host& 8217;s owner. The concept & 8230;

2. ACTIVE DEFENSE Imagine a network where there are Nhostswithapar- ticularsetof vulnerabilities, and then a worm is released that is able to exploit one or more of these. We suppose that a host infected by this worm scans the network look- ingforvulnerable hosts it may infect. We assume thata scan consists ofarandom selection of an IP address—if that host is susceptible and uninfected it immediately becomes infected. In our discrete model we assume that the address selection is oblivious to the state of the network. This means that non-uniform random scanning can be ac- commodatedinthe model, so long as the sampling is not affected by any knowledge of other hosts, infected or not. This does not preclude the sort of stratified sampling seen in some worms (where hosts & 8220;closer& 8221;to the infected one are sampled with higher probability), but it does preclude adynamic partitioning of the search space based on coordination among infected hosts. We assume a random delay of time between successive scans from a host, once again assuming that the sampling is independent of network state. Under these assumptions we can picture the behavior ofa worm on a time-line populated with scan events. Each scan event has a source and destination identity. Each of the sus- ceptiblehostshasa state of uninfected, or infected. A scan event that has an uninfected hostas destination changes that host& 8217;sstate, and thereafter it contributes to the scanning. (It is straightforward to augment the model to account for latency between whenascanissent and when it is received, we have not done so for simplicity of exposition).

Buy It at Lowest Price on Amazon

Models of Active Worm Defenses.Pdf

Rating:
2.5 out of 5 by Book123