If a category does not exist then you cannot compare it. Incomparable is when you
have two disjointed sensitivity labels, that is a category in one of the labels is not in the other label.
"Because neither label contains all the categories of the other, the labels can't be compared.
They're said to be incomparable"
COMPARABILITY:
The label:
TOP SECRET [VENUS ALPHA]
is "higher" than either of the labels:
SECRET [VENUS ALPHA] TOP SECRET [VENUS]
But you can't really say that the label:
TOP SECRET [VENUS]
is higher than the label:
SECRET [ALPHA]
Because neither label contains all the categories of the other, the labels can't be compared.
They're said to be incomparable. In a mandatory access control system, you won't be allowed
access to a file whose label is incomparable to your clearance.
The Multilevel Security policy uses an ordering relationship between labels known as the
dominance relationship. Intuitively, we think of a label that dominates another as being "higher"
than the other. Similarly, we think of a label that is dominated by another as being "lower" than the
other. The dominance relationship is used to determine permitted operations and information
flows.
DOMINANCE
The dominance relationship is determined by the ordering of the Sensitivity/Clearance component
of the label and the intersection of the set of Compartments.
Sample Sensitivity/Clearance ordering are:
Top Secret > Secret > Confidential > Unclassified
s3 > s2 > s1 > s0
Formally, for label one to dominate label 2 both of the following must be true:
The sensitivity/clearance of label one must be greater than or equal to the sensitivity/clearance of
label two.
The intersection of the compartments of label one and label two must equal the compartments of
label two.
Additionally:
Two labels are said to be equal if their sensitivity/clearance and set of compartments are exactly
equal. Note that dominance includes equality.
One label is said to strictly dominate the other if it dominates the other but is not equal to the other.
Two labels are said to be incomparable if each label has at least one compartment that is not
included in the other's set of compartments.
The dominance relationship will produce a partial ordering over all possible MLS labels, resulting
in what is known as the MLS Security Lattice.
The following answers are incorrect:
The number of classification in the two labels is different. Is incorrect because the categories are
what is being compared, not the classifications.
Neither label contains all the classifications of the other. Is incorrect because the categories are
what is being compared, not the classifications.
the number of categories in the two labels is different. Is incorrect because it is possibe a category exists more than once in one sensitivity label and does exist in the other so they would be comparable.
Reference(s) used for this question:
OReilly - Computer Systems and Access Control (Chapter 3) http://www.oreilly.com/catalog/csb/chapter/ch03.html and http://rubix.com/cms/mls_dom

The trusted computing base (TCB) is a collection of all the hardware, software, and firmware components within a system that provide some type of security and enforce the system's security policy. The TCB does not address only operating system components, because a computer system is not made up of only an operating system.
Hardware, software components, and firmware components can affect the system in a negative or positive manner, and each has a responsibility to support and enforce the security policy of that particular system. Some components and mechanisms have direct responsibilities in supporting the security policy, such as firmware that will not let a user boot a computer from a USB drive, or the memory manager that will not let processes overwrite other processes' data. Then there are components that do not enforce the security policy but must behave properly and not violate the trust of a system. Examples of the ways in which a component could violate the system's security policy include an application that is allowed to make a direct call to a piece of hardware instead of using the proper system calls through the operating system, a process that is allowed to read data outside of its approved memory space, or a piece of software that does not properly release resources after use.
To assist with the evaluation of secure products, TCSEC introduced the idea of the Trusted
Computing Base (TCB) into product evaluation. In essence, TCSEC starts with the principle that there are some functions that simply must be working correctly for security to be possible and consistently enforced in a computing system. For example, the ability to define subjects and objects and the ability to distinguish between them is so fundamental that no system could be secure without it. The TCB then are these fundamental controls implemented in a given system, whether that is in hardware, software, or firmware. Each of the TCSEC levels describes a different set of fundamental functions that must be in place to be certified to that level.
The link below will take you to a one page document that describes the high-level requirements that any TCB would need to meet to achieve each division or class
(essentially a subdivision) of the TCSEC rating. See details at:
https://www.freepracticetests.org/documents/TCB.pdf
Reference(s) used for this question:
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (pp. 359-360).
McGraw-Hill. Kindle Edition.
and
Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third
Edition ((ISC)2 Press) (Kindle Locations 17936-17943). Auerbach Publications. Kindle
Edition.

Explanation/Reference:
Explanation:
The Software Capability Maturity Model (CMM) is based on the premise that the quality of a software product is a direct function of the quality of its associated software development and maintenance processes. It introduces five maturity levels that serve as a foundation for conducting continuous process improvement and as an ordinal scale for measuring the maturity of the organization involved in the software processes.
CMM has Five Maturity Levels of Software Processes:
The initial level: processes are disorganized, even chaotic. Success is likely to depend on individual

efforts, and is not considered to be repeatable as processes would not be sufficiently defined and documented to allow them to be replicated.
The repeatable or managed level: basic project management techniques are established, and

successes could be repeated as the requisite processes would have been made established, defined, and documented.
The defined level: an organization has developed its own standard software process through greater

attention to documentation, standardization, and integration.
The quantatively managed level: an organization monitors and controls its own processes through data

collection and analysis.
The optimized level: processes are constantly being improved through monitoring feedback from

current processes and introducing innovative processes to better serve the organization's particular needs.
Incorrect Answers:
A: Total Quality Management (TQM) is a management approach of an organization centered on quality, based on the participation of all its members and aiming at long term success through customer satisfaction.
B: The Integrated Design, Evaluation, and Assessment of Loadings (IDEAL) model is a post-construction water quality model for designing storm water best management practices. It is not a software development model.
D: The Spiral model uses an iterative approach to software development with an emphasis on risk analysis. The iterative approach allows new requirements to be addressed as they are uncovered. It is a good model for complex projects that have fluid requirements.
The spiral model has four main phases:
Planning

Risk analysis: ensures that all issues are actively reviewed and analyzed.

Development and testing: prototype testing takes place early in the development project, and feedback

based upon these tests is integrated into the following iteration of steps.
Evaluation: the customer evaluates the product in its current state and provides feedback, which is an

input value for the following iteration of steps.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, pp. 62, 1115-
1116, 1120-1122
http://en.wikipedia.org/wiki/Capability_Maturity_Model
https://en.wikipedia.org/wiki/Total_quality_management
https://en.wikipedia.org/wiki/IDEAL_model

Explanation/Reference:
Explanation:
A virtual private network (VPN) is a secure, private connection through an untrusted network. VPN technology requires a tunnel to work and it assumes encryption.
Incorrect Answers:
B: A one-time password is not the same as a VPN.
C: Tunnel, not pipeline, can be used as a name for a VPN.
D: Tunnel, not bypass, can be used as a name for a VPN.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 702