domain protection and Access matrix and its implementation


A protection domain specifies the resources that a process may access. Each domain defines a set of objects and the types of operations that may be invoked on each object


https://youtu.be/uFIzD1k5S5U



Access rights are commonly associated with protection domains.
 A process executes inside a protection domain.
The process then has the rights and privileges of the domain.
Thus many processes can have the same rights if they execute in the same domain. There are too many subjects, objects and access rights in a normal system to explicitly keep information about all of them. So this combining is the first attempt to decrease the amount of protection information which the system needs to maintain. A domain is a collection of ordered pairs

  • Access matrix and its implementation


https://youtu.be/2YIhzk7tJI8

Access matrix in Operating System









Access Matrix is a security model of protection state in computer system. It is represented as a matrix. Access matrix is used to define the rights of each process executing in the domain with respect to each object. The rows of matrix represent domains and columns represent objects. Each cell of matrix represents set of access rights which are given to the processes of domain means each entry(i, j) defines the set of operations that a process executing in domain Di can invoke on object Oj.
F1F2F3PRINTER
D1readread
D2print
D3readexecute
D4read writeread write


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