IT Governance, Risk, and Compliance » Central Processing Unit

Essential Operating System Protection Mechanisms – Part VI

Robert Davis — Sat, 27 Oct 2012 02:18:06 +0000

Sustaining information integrity requires operating system protection

Usually, IT network environments orchestrate direction and control through an operating system installed to coordinate processes; including application software. In other words, an operating system performs most generally accepted management functions for IT processes.

Without an operating system certain functions, such as multiprogramming, simply would not be an available processing option, and many functions like I/O completion testing would have to be performed directly by a programmer. Therefore, operating systems are the primary catalyst sustaining efficient and effective information integrity. If this viewpoint is adopted throughout the entity, IT owners should ensure adequate protection mechanisms are installed with employed operating systems.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Dictionary.com Unabridged (v 1.1). rev. ed. New York, NY: Random House. http://dictionary.reference.com/browse/linkage editor (accessed: August 30, 2008).

Lyon, Lockwood and Kenniston W. Lord. CDP Review Manual: Covering the ICCP, CDP, CSP, and CCP Examinations, 5th ed. New York, NY: Van Nostrand Reinhold, 1991. 130-2

Minasi, Mark. Complete PC Upgrade and Maintenance Guide, 8th ed. San Francisco, CA: SYBEX, 1997. 263-4

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 239

Silbershatz, Abraham and Peter B. Galvin. Operating System Concepts, 4th ed. Gainesville, FL: Addison-Wesley, 1995. 49-50

“View Part I of the Essential Operating System Protection Mechanisms series here”

Post Note: “Essential Operating System Protection Mechanisms – Part VI” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”

Essential Operating System Protection Mechanisms – Part V

Robert Davis — Thu, 25 Oct 2012 03:31:08 +0000

Technically, the user program subroutine integration process is known as linkage editing. Linkage editing poses two risks: the unauthorized use of subroutines and the unauthorized suppression of subroutines that should accept utilization. In the first case, an application program might utilize a job control (script) statement requesting the services of an unauthorized subroutine that performs an illegal task. In the second case, the program might use a script statement that suppresses the services of a required subroutine. Consequently, policies and procedures should be implemented to ensure:

error messages are displayed or other action taken when reference is made to unauthorized subroutines, or when external references are unsolved
the operating system maintains a log of program usage
the linkage editor of the operating system maintains a processing history of each program, including control statements utilized

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Dictionary.com Unabridged (v 1.1). rev. ed. New York, NY: Random House. http://dictionary.reference.com/browse/linkage editor (accessed: August 30, 2008).

Lyon, Lockwood and Kenniston W. Lord. CDP Review Manual: Covering the ICCP, CDP, CSP, and CCP Examinations, 5th ed. New York, NY: Van Nostrand Reinhold, 1991. 130-2

Minasi, Mark. Complete PC Upgrade and Maintenance Guide, 8th ed. San Francisco, CA: SYBEX, 1997. 263-4

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 239

Silbershatz, Abraham and Peter B. Galvin. Operating System Concepts, 4th ed. Gainesville, FL: Addison-Wesley, 1995. 49-50

“View Part I of the Essential Operating System Protection Mechanisms series here”

Post Note: “Essential Operating System Protection Mechanisms – Part V” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”

Essential Operating System Protection Mechanisms – Part IV

Robert Davis — Sat, 20 Oct 2012 00:44:59 +0000

Preventing infinite program loops

Processor protection deters infinite program loops that could affect availability. Inserting a timer prevents programs from being stuck in infinite loops, and never returning control to the operating system. The operating system timer can be fixed or variable. However, the system parameter for the timer should be set at a generally accepted practice range with instructions to interrupt the operating system timer considered a privileged authorization for incident prevention.

Reducing the risk of IT program manipulation

Lastly, user program protection dictates user access to shared user resources. Rather than include all necessary instructions in an application program, many programs simply reference other programs, or subroutines, that may be available in the program library. When a program makes a reference to subroutine, it is the operating system that calls the subroutine in from the library and makes it available to the requesting program.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Dictionary.com Unabridged (v 1.1). rev. ed. New York, NY: Random House. http://dictionary.reference.com/browse/linkage editor (accessed: August 30, 2008).

Lyon, Lockwood and Kenniston W. Lord. CDP Review Manual: Covering the ICCP, CDP, CSP, and CCP Examinations, 5th ed. New York, NY: Van Nostrand Reinhold, 1991. 130-2

Minasi, Mark. Complete PC Upgrade and Maintenance Guide, 8th ed. San Francisco, CA: SYBEX, 1997. 263-4

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 239

Silbershatz, Abraham and Peter B. Galvin. Operating System Concepts, 4th ed. Gainesville, FL: Addison-Wesley, 1995. 49-50

“View Part I of the Essential Operating System Protection Mechanisms series here”

Post Note: “Essential Operating System Protection Mechanisms – Part IV” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”

Essential Operating System Protection Mechanisms – Part III

Robert Davis — Thu, 18 Oct 2012 01:18:01 +0000

Intel Central Processing Unit (CPU)

A potential consequence for a breach in memory protection is a halt in all current processing. Therefore, the operating system should monitor the partitions to ensure that no program coding or data are moved into the wrong partition to prevent information corruption and unauthorized manipulation. Furthermore, operating systems should check to ensure data read into devices from other media are of the correct length. The operating system’s data length check prevents errors, such as blocks of records being too long for the memory buffer storage area.

Controlling privileged instructions

I/O allocation and control dynamically matches and assigns channels and devices with the processes’ particular requirements, monitors the status, and controls operations. Where online features are part of the IT configuration, communication with a terminal control unit (TCU) or front-end processor (FEP) are typically included in operating system duties. I/O protection prevents users from accessing privileged instructions.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Dictionary.com Unabridged (v 1.1). rev. ed. New York, NY: Random House. http://dictionary.reference.com/browse/linkage editor (accessed: August 30, 2008).

Lyon, Lockwood and Kenniston W. Lord. CDP Review Manual: Covering the ICCP, CDP, CSP, and CCP Examinations, 5th ed. New York, NY: Van Nostrand Reinhold, 1991. 130-2

Minasi, Mark. Complete PC Upgrade and Maintenance Guide, 8th ed. San Francisco, CA: SYBEX, 1997. 263-4

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 239

Silbershatz, Abraham and Peter B. Galvin. Operating System Concepts, 4th ed. Gainesville, FL: Addison-Wesley, 1995. 49-50

“View Part I of the Essential Operating System Protection Mechanisms series here”

Post Note: “Essential Operating System Protection Mechanisms – Part III” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”

Essential Operating System Protection Mechanisms – Part II

Robert Davis — Sat, 13 Oct 2012 00:40:27 +0000

Deployable operating system protection mechanisms

In most instances, the purpose of operating system protection mechanisms are to prevent programs from interfering with each other during processing and to ensure there are no errors in referencing of subroutines in the program library; as well as ensure no unauthorized changes are made to authorized instructions.

Regarding entity software controls, all of the functions utilizing the Central Processing Unit (CPU) and associated storage as well as connected input and output devices are potential candidates for operating system defense strategies. Tactically, four primary operating system protection mechanisms are deployable: memory, I/O, processor, and user program controls.

Protecting against unauthorized modification

Memory protection restricts unauthorized modification to privileged programs. The operating system can partition associated memory into segments. Under this condition, each application program or program set will be assigned a particular memory partition. This allows several programs to process simultaneously in a multiprogramming environment, without interfering with each other.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Dictionary.com Unabridged (v 1.1). rev. ed. New York, NY: Random House. http://dictionary.reference.com/browse/linkage editor(accessed: August 30, 2008).

Lyon, Lockwood and Kenniston W. Lord. CDP Review Manual: Covering the ICCP, CDP, CSP, and CCP Examinations, 5th ed. New York, NY: Van Nostrand Reinhold, 1991. 130-2

Minasi, Mark. Complete PC Upgrade and Maintenance Guide, 8th ed. San Francisco, CA: SYBEX, 1997. 263-4

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 239

Silbershatz, Abraham and Peter B. Galvin. Operating System Concepts, 4th ed. Gainesville, FL: Addison-Wesley, 1995. 49-50

“View Part I of the Essential Operating System Protection Mechanisms series here”

Post Note: “Essential Operating System Protection Mechanisms – Part II” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”

Essential Operating System Protection Mechanisms – Part I

Robert Davis — Thu, 11 Oct 2012 12:39:45 +0000

Third Generation iPod Nano With Embedded Operating System 1.1.3

From mainframe computers to industrial robots to cellular phones, a variety of operating systems are available for deployment. Nevertheless, reflective of current capabilities, an IT operating system is software that controls the execution of electronically encoded instructions and may provide scheduling, debugging, input/output (I/O) control, accounting, compilation, storage assignment, job management, as well as other related services. Of these other related services, operating system protection mechanisms are crucial to ensuring information integrity.

Operating system processor functionality

Operating system functionality is determined by the lead software manufacture. However, operating systems consist of a kernel and at least one processor; with each operating system processor having specific functions that are executed based on user and/or program interface syntax. Whereby, modern operating system processors commonly perform defined process management, memory management, device management, storage management, as well as application-interface and/or user-interface related tasks.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Dictionary.com Unabridged (v 1.1). rev. ed. New York, NY: Random House. http://dictionary.reference.com/browse/linkage editor(accessed: August 30, 2008).

Lyon, Lockwood and Kenniston W. Lord. CDP Review Manual: Covering the ICCP, CDP, CSP, and CCP Examinations, 5th ed. New York, NY: Van Nostrand Reinhold, 1991. 130-2

Minasi, Mark. Complete PC Upgrade and Maintenance Guide, 8th ed. San Francisco, CA: SYBEX, 1997. 263-4

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 239

Silbershatz, Abraham and Peter B. Galvin. Operating System Concepts, 4th ed. Gainesville, FL: Addison-Wesley, 1995. 49-50

Post Note: “Essential Operating System Protection Mechanisms – Part I” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”

A Few Fundamentals of Networking Electronically Encoded Data – Part IV

Robert Davis — Sat, 22 Sep 2012 00:07:07 +0000

In TDM (typically utilized for digital signals) a device is given a specific time slot during which it can utilize a particular channel. In contrast, with FDM (typically utilized for analog signals) the channel is subdivided into sub-channels, each with a different frequency width that is assigned to a specific signal.

Through TDM incorporation, optical-fiber networks can use dense wavelength-division multiplexing (DWDM), also known as wave division multiplexing (WDM), in which different data signals are sent in different wavelengths of light in the fiber-optic medium.

How networking services are maintained by enterprises

Network Administration is the function designated to maintain a secure as well as reliable on-line communications network and serves as liaison with user departments to resolve network needs and problems. Specifically, this function is generally responsible for maintaining network security, maintaining optimum system performance, and providing technical assistance to users. Thus, just like the ‘telephone service technician‘, the network administrator should be considered the specialist capable of reestablishing communication if service quality is diminished.

“View Part I of the A Few Fundamentals of Networking Electronically Encoded Data series here”

Post Note: “A Few Fundamentals of Networking Electronically Encoded Data – Part IV” was originally published through Suite101.com under the title “A Few Fundamentals of Networking Electronically Encoded Data”

A Few Fundamentals of Networking Electronically Encoded Data – Part III

Robert Davis — Thu, 20 Sep 2012 01:09:51 +0000

Packet assembly and disassembly between telecommunication links

Input or output (I/O) channels are paths along which datum are transmitted to and from primary storage. These communication channels also handle the transfer of datum to and from I/O devices. As a result, this function can relieve the Central Processing Unit (CPU) of responsibility for data transfers to and from I/O devices, increase the number of input and output operations that can be performed simultaneously and reduce the time a CPU must wait for datum to arrive from, or sent to, an I/O device.

A common IT transmission technique for telecommunications is multiplexing. Multiplexing is the process of transmitting multiple (but separate) signals simultaneously over a single channel or line. The two main types of multiplexing methods are time-division multiplexing (TDM) and frequency-division multiplexing (FDM). Because the signals are sent in one complex transmission, the receiving end has to separate the individual signals through de-multiplexing.

“View Part I of the A Few Fundamentals of Networking Electronically Encoded Data series here”

Post Note: “A Few Fundamentals of Networking Electronically Encoded Data – Part III” was originally published through Suite101.com under the title “A Few Fundamentals of Networking Electronically Encoded Data”

Hardware Protection… Dust, Temperature, and Humidity – Oh My! – Part V

Robert Davis — Mon, 05 Oct 2009 19:45:05 +0000

Decreasing computer hardware replacement cost has not eliminated the need for adequate environmental protection. To avoid humidity corruption, information security managers should verify humidity and temperature levels are maintained within the operating range specified in supplier documentation for deployed IT. Periodically, an information security professional should inspect for obvious external influences such as close placement to air conditioners, elevator shafts, industrial equipment or other sources of potential atmospheric variations. If a high level of reliability is required, then optimal conditions should be maintained. Maintaining equipment at the optimum climate range aids in protecting hardware from corrosion problems associated with high humidity levels and failures caused by static discharge when humidity is too low.

“View Part I of the Hardware Protection… Dust, Temperature, and Humidity – Oh My! series here“

Hardware Protection… Dust, Temperature, and Humidity – Oh My! – Part IV

Robert Davis — Thu, 01 Oct 2009 23:22:55 +0000

IT can, and does, operate within a wide humidity range. Seasonal humidity changes are usually easier to control than hourly fluctuations. Under either circumstance, normally the primary environmental concern is preventing conditions that permit humidity alterations where condensation is the result. Data culled from analysis of historical psychrometer reading can be instrumental in determining seasonal changes or outside influences. Technically, a psychrometer is a hydrometer consisting of two thermometers with bulbs, one wet and one dry. One bulb is kept wet so the cooling that results from evaporation permits registration of a lower temperature than the dry bulb. The difference between the two readings constitutes a measure of atmospheric dryness.

“View Part I of the Hardware Protection… Dust, Temperature, and Humidity – Oh My! series here“