The following paper will discuss the Unix Operating System and how to implement a protection scheme that permits multiple users access to one file, with the exception of denying access to a particular group of users to the same file. Including the importance of protecting file sharing permissions to users.
Perhaps a business has a system that will support 5,000 users, however only 4,990 users are granted permissions to access one particular file. In order to grant access to 4,990 users, restricted authority is given. This will ensure that only the file needed is available to specific users and will help protect other data and system information from being accessed without permission. If restrictions are not implemented this could cause security issues, and breach of information, could diminish the integrity of the business. In some systems a security policy may be imposed to users whom have rights to access particular files, as well as specific classification to own those rights. (Low, Marie 1993)
UNIX file systems uses a protection scheme that provides sharing and protection of files. By using a protection scheme, owners of said file, manage the control over who will have access to modify, write, and read the files information. The owner may grant access to a group of users, otherwise defined as a subset of user, which will only allow the group of members to create subsets of operations, thus the owner can make changes as necessary. (Stallings, 2012)
If a user creates a file in UNIX, that file and permissions are owned by that particular user. In order to fully access a file, when a user wants to perform a task or operation on a file, the user needs to have read access, write access and execute access. In some instances, the owner may only give one of the accesses, which will limit what other users are allowed to do. Each user has an ID that is instantly compared to the owner’s attributes in order to determine if the asking user
References: Levine, Levine, Unix for Dummies, http://www.dummies.com/how-to/content/exploring- nfs-in-unix.html Low, Marie, ACM SIGOPS Operating Systems Review, ISSN 0163-5980, 01/1993, Volume 27, Issue 1, pp. 33 - 50 Stallings, W. (2012). Operating systems: Internals and design principles (7th ed.). Boston, MA: Prentice Hall.