In the web era, and with the growing use of mobile computing technology, the need for security is greater than ever across the entire spectrum of IT. As with reliability, the security of a system is dependent on many functional areas, of which the operating system is only one. However, the security functions in UNIX systems have continued to evolve as they have been deployed in ever-more critical roles. The main areas of focus have been on improving control over allowable actions by users and administrators; supporting data encryption in the OS; and improving tools to help administrators make sure their systems have been properly secured. Some systems also monitor application and user behavior at the level of the kernel in order to detect signs of intrusion. Support for Multilevel Security (MLS) also remains an important requirement in certain environments.

Below are some of the key UNIX functions to maintain security at the OS level. Click on one f the links to see how the systems compare in supporting these functions:

	Role-Based Access Control (RBAC) (3 ratings)
	Storage Encryption (6 ratings)
	Trusted Execution (3 ratings)
	Security configuration (6 ratings)
	Multilevel Security (3 ratings)
	Host-based Intrusion Detection (4 ratings)