|
|
|
Violation Processing To understand what has actually taken place during a computing session, it is often necessary to have a mechanism that captures the detail surrounding access, particularly accesses occurring outside the bounds of anticipated actions. Any activity beyond those designed into the system and specifically permitted by the generally established rules of the site should be considered a violation. Capturing activity permits determination of whether a violation has occurred or whether elements of software and hardware implementation were merely omitted, therefore requiring modification. In this regard, tracking and analyzing violations are equally important. Violation tracking is necessary to satisfy the requirements for the due care of information. Without violation tracking, the ability to determine excesses or unauthorized use becomes extremely difficult, if not impossible. For example, a general user might discover that, because of an administrative error, he or she can access system control functions. Adequate, regular tracking highlights such inappropriate privileges before errors can occur. An all-too-frequently overlooked component of violation processing is analysis. Violation analysis permits an organization to locate and understand specific trouble spots, both in security and usability. Violation analysis can be used to find:
A specialized form of violation examination, intrusion analysis (i.e., attempting to provide analysis of intrusion patterns), is gaining increased attention. As expert systems gain in popularity and ability, their use in analyzing patterns and recognizing potential security violations will grow. The need for such automated methods is based on the fact that intrusions continue to increase rapidly in quantity and intensity and are related directly to the increasing number of personal computers connected to various networks. The need for automated methods is not likely to diminish in the near future, at least not until laws surrounding computer intrusion are much more clearly defined and enforced. Currently, these laws are not widely enforced because damages and injuries are usually not reported and therefore cannot be proven. Overburdened law enforcement officials are hesitant to actively pursue these violations because they have more pressing cases (e.g., murder and assault). Although usually less damaging from a physical injury point of view, information security violations may be significantly damaging in monetary terms. In several well-publicized cases, financial damage has exceeded $10 million. Not only do violation tracking and analysis assist in proving violations by providing a means for determining user errors and the occasional misuse of data, they also provide assistance in preventing serious crimes from going unnoticed and therefore unchallenged. Clipping Levels Organizations usually forgive a particular type, number, or pattern of violations, thus permitting a predetermined number of user errors before gathering this data for analysis. An organization attempting to track all violations, without sophisticated statistical computing ability, would be unable to manage the sheer quantity of such data. To make a violation listing effective, a clipping level must be established. The clipping level establishes a baseline for violation activities that may be normal user errors. Only after this baseline is exceeded is a violation record produced. This solution is particularly effective for small- to medium-sized installations. Organizations with large-scale computing facilities often track all violations and use statistical routines to cull out the minor infractions (e.g., forgetting a password or mistyping it several times). If the number of violations being tracked becomes unmanageable, the first step in correcting the problems should be to analyze why the condition has occurred. Do users understand how they are to interact with the computer resource? Are the rules too difficult to follow? Violation tracking and analysis can be valuable tools in assisting an organization to develop thorough but useable controls. Once these are in place and records are produced that accurately reflect serious violations, tracking and analysis become the first line of defense. With this procedure, intrusions are discovered before major damage occurs and sometimes early enough to catch the perpetrator. In addition, business protection and preservation are strengthened. Transparency Controls must be transparent to users within the resource protection schema. This applies to three groups of users. First, all authorized users doing authorized work, whether technical or not, need to feel that computer system protection requirements are reasonably flexible and are not counterproductive. Therefore, the protection process must not require users to perform extra steps; instead, the controls should be built into the computing functions, encapsulating the users’ actions and producing the multiple commands expected by the system. The second group of users consists of authorized users attempting unauthorized work. The resource protection process should capture any attempt to perform unauthorized activity without revealing that it is doing so. At the same time, the process must prevent the unauthorized activity. This type of process deters the user from learning too much about the protective mechanism yet controls permitted activities. The third type of user consists of unauthorized users attempting unauthorized work. With unauthorized users, it is important to deny access transparently to prevent the intruder from learning anything more about the system than is already known.
|