Deisgning security systems for a digital government’s multidomain environment requires a careful balancing act between providing convenient access and carefully monitoring permissions.

Despite occasional setbacks, digital government projects now appear firmly on the road to fulfilling their promise of making civil and political processes mor eaccessible than ever.

With the dramatic growth of information exchanges within and between organizations, major concerns emerge about the assurance of information.  Without clear knowledge of the true needs for information assurance, a company may employ local, specialized solutions that are too restrictive, or nor comprehensive.  On the other hand, cost-effective, variable integrity and variable security may be economically justifiable and adequate for ertain situations and decisions.  Therefore, a new definition of information assurane has been developed following the TQM approach.  It describes assurance as a combination of information security, integrity, and significance. The requirements of information assurance are presented and have been justified on the basis of concrete results obtained from the lab experiments that were conducted.  The exeriments and results have been briefly discussed in this paper.

A lab experiment has been perfrmed using an ERP simulator to study the impact of information failure on the results of a company.  Two scenerios have been considered: correct but delayed information, and wrong information.  The influence of the length of delay, of the error size, and of the dataet concerned by the failure have also been studied.  It follows from the analysis that: -The consequences of a given information failure depend on the dataset in which the failure occurs. -For a given dataset, information failures impact depends on the failure type. -The influence of the length of delay depends on the dataset. -The influence of the error size depends on the dataset. So far companies employ local, specialized solutions that are too restrictive, or not compehensive.  The experiments presented in this paper justify economically the use of solutions with variable assurance in ERP sysems.  They also provide directions for the design of autonomous agents to handle these assurance problems.

Denial of service (DoS)attack on the Internet has become a pressing problem.In this paper,we describe and evaluate route-based distributed packet .ltering (DPF),a novel ap- proach to distributed DoS (DDoS)attack prevention.We show that DPF achieves proactiveness and scalability,and we show that there is an intimate relationship between the e .ectiveness of DPF at mitigating DDoS attack and power- law network topology.