Distributed Software Engineering

4. Security

Security is a very critical issue in many systems, especially distributed systems. This is because the system is distributed across a network over many devices, and so there may be more ways for outsiders to access the system who do not have permission to do such. A security breach is considered to be any time an unsafe state is reached within the system. An unsafe state is one in which data can be illegally intercepted, interrupted, modified, or fabricated. Since a distributed system is made up of various smaller systems with the possibility of each system being managed separately, it becomes very important that all parts of the distributed system be managed uniformly and completely to prevent security breaches. Furthermore, in the case that a security breach has been made on one sub-system, it becomes very possible that the attacker can gain access to other parts of the system. In this case, the attacker may even be able to make it appear that the accesses to the other parts of the system were made legally [1, 6, 7]. Access control, bracket capabilities, and the formal protection model are methods of ensuring a secure and safe distributed system environment.

4.1 Access Control

Access control is described as “the process of regulation of the kind of access (e.g. – read access, write access, no access) an entity has to the system resources” [7]. Access control can therefore prevent and enable parts of the systems to perform certain actions and access specific files and data. Access control lists are used to store the privilege information. Entries are stored in access control lists that specify whether an entity has the right to either access, write, or execute certain sections of a system [8].

A comm...

... middle of paper ...

...a, 2008.

[6] Appelbe, Akyildiz, Benson. A FormalProtection Model of Security in Centralized, Parallel, and Distributed Systems. Georia Institute of Technology. 1990.

[7] Shreyas, Doshi. Software Engineering for Security: Towards Architecting Secure Software. University of California, Irvine, CA. 2001.

[8] Access Control Lists. Microsoft Development Network. Internet: http://msdn.microsoft.com/en-us/library/aa374872(VS.85).aspx. [Oct. 12, 2011].

[9] How Permissions Work. Microsoft TechNet. Internet: http://technet.microsoft.com/en-us/library/cc783530(WS.10).aspx. [Oct. 12, 2011].

[10] Clarskon, Michael. Access Control. Cornell University. Internet: http://www.cs.cornell.edu/courses/cs513/2007fa/NL.accessControl.html. [Oct. 12, 2011].

[11] Evered, Mark. Bracket Capabilities for Distributed Systems Security. University of New England, Armidale, Australia. 2002.