Case Study no. 3 in Operating Systems

In a multiprogramming and time-sharing environment, the users can share data, resources and other information simultaneously. This is because of the multitasking capability of these environments. In a multiprogramming environment, the system allocates CPU resources for the concurrent programs running in the system. Time-sharing allows users to share information, resources and other data through this.

However, time-saving and efficient as it may be, there are problems related to file security that are associated with multiprogramming and time-sharing environments. In this case study, I will mention the two common problems with these environments.

The first security problem is the privacy of user data. As mentioned earlier, these environments allow users to share data and resources. This compromises the privacy of data, because this allows one user to copy data without permission from the other user, as shown in an instance when an administrator is running a decryption protocol, and one of the users has managed to steal the decryption key. This could result in a lot of encrypted (commonly top-secret) files to be decrypted, revealing some vital information that could be very detrimental to the user’s privacy.

The second problem related to security in a multiprogramming and time-sharing environment is the vulnerability of data to virus infection. As long as there is simultaneous sharing of resources, data and other information, there is a very big possibility of transferring infected files from one user to another. For example, a user may (usually unknowingly) transfer an infected program from one user to another, and as the other user executes the (infected) program, it will start to infect his files and his computer and the virus will start to spread among the other users’ computers, infecting them as well. Another example is that of a server infecting all of the computers in the system because of an infected file or a malware in the server itself that targets every computer under its control.

Taking these security problems into consideration, I can then say that ensuring the same degree of security in time-sharing machines as it would be in dedicated machines is impossible because time-sharing machines are prone to serious security problems such as malicious attacks by hackers, and dedicated machines are known to be prone to hard disk crashes and data corruption. Time-sharing machines, because the data, resources and other information are open for access to everyone, can be used to exploit the privacy of users and they can also be used to spread malicious software and infected files to other users, thus infecting their data and computers.

Dedicated machines, on the other hand, can also be infected with viruses if there is no firewall. A firewall is a software (or sometimes, hardware) package that can control which ports on your server are open to the Internet, and sometimes detect intrusion attempts. If there is no firewall installed, or if the firewall is installed but disabled, there is a very big risk of intrusion and infection, which in turn will cause data corruption and hard disk crashes.

In conclusion, there will always be problems and issues in multiprogramming and time-sharing environments with regards to security such as virus intrusions, compromisation of data privacy, and many more. That is why we cannot ensure the same degree of security in both environments as well as in dedicated machines.