OPERATING SYSTEMS

Case Study 3

In a multiprogramming and time-sharing environment, several users share the system simultaneously. This situation can result in various security problems. Name at least two of these problems. Can we ensure the same degree of security in a time-share machine as we have in a dedicated machine? Explain your answer

No, because since any protection scheme devised by humans
can inevitably be broken by a human, and the more complex the scheme, the more difficult it is to feel confident of its correct implementation.

This is because in which a system which is consciously intended to have certain restricted purposes or functions becomes more and more elaborate over time, and more and more of its mechanisms become obscure and hidden in their inputs and outputs. I think maybe there are some natural examples of this kind of movement towards baroque complexity. But baroque complexity dies out when it becomes actively dysfunctional within some kind of fitness landscape. Human systems can achieve this kind of opacity by accident and by intent. Accidental drift towards a system where no one really understands how cause and effect work within the system happens in institutional life all the time. Stakeholders in individual parts or aspects of a system are inclined to expand the influence or size of their mechanism. New forces or powers outside an institution are often accommodated by being incorporated within it. Procedures or heuristics used by an institution in its everyday business sometimes take on a life of their own, especially when they are incorporated into technological infrastructure and automated in some respect. Complexity happens by intent when human agents with some degree of authority over an institutional system want to block off direct access or control to some of its inner workings as a safeguard against easy tampering. It also happens when someone with an interest in a particular system believes that secrecy and confusion will instrumentally advance that interest. I think there are quite a few examples of authorities who set out to make it hard for an outsider to understand how a system or process works only to find that in making it hard for outsiders to understand, they’ve made it hard for everyone, that even people in control who thought that secrecy would conceal selectively have found that it conceals indiscriminately.