ISC SSCP - Systems Security Certified Practitioner Exam

Answer : D

Explanation: Because the optical unit utilizes a camera and infrared light to create the images, sun light can impact the aperture so it must not be positioned in direct light of any type. Because the subject does not need to have direct contact with the optical reader, direct light can impact the reader.
An Iris recognition is a form of biometrics that is based on the uniqueness of a subject's iris.
A camera like device records the patterns of the iris creating what is known as Iriscode.
It is the unique patterns of the iris that allow it to be one of the most accurate forms of biometric identification of an individual. Unlike other types of biometics, the iris rarely changes over time. Fingerprints can change over time due to scaring and manual labor, voice patterns can change due to a variety of causes, hand geometry can also change as well. But barring surgery or an accident it is not usual for an iris to change. The subject has a high-resoulution image taken of their iris and this is then converted to Iriscode. The current standard for the Iriscode was developed by John Daugman. When the subject attempts to be authenticated an infrared light is used to capture the iris image and this image is then compared to the Iriscode. If there is a match the subject's identity is confirmed. The subject does not need to have direct contact with the optical reader so it is a less invasive means of authentication then retinal scanning would be.
Reference(s) used for this question:
AIO, 3rd edition, Access Control, p 134.
AIO, 4th edition, Access Control, p 182.
Wikipedia - http://en.wikipedia.org/wiki/Iris_recognition
The following answers are incorrect:
concern that the laser beam may cause eye damage. The optical readers do not use laser so, concern that the laser beam may cause eye damage is not an issue. the iris pattern changes as a person grows older. The question asked about the physical installation of the scanner, so this was not the best answer. If the question would have been about long term problems then it could have been the best choice. Recent research has shown that Irises actually do change over time: http://www.nature.com/news/ageing- eyes-hinder-biometric-scans-1.10722 there is a relatively high rate of false accepts. Since the advent of the Iriscode there is a very low rate of false accepts, in fact the algorithm used has never had a false match. This all depends on the quality of the equipment used but because of the uniqueness of the iris even when comparing identical twins, iris patterns are unique.

Answer : B

Explanation: A Sensitivity label must contain at least one classification and one category set.
Category set and Compartment set are synonyms, they mean the same thing. The sensitivity label must contain at least one Classification and at least one Category. It is common in some environments for a single item to belong to multiple categories. The list of all the categories to which an item belongs is called a compartment set or category set.
The following answers are incorrect:
the item's classification. Is incorrect because you need a category set as well. the item's category. Is incorrect because category set and classification would be both be required.
The item's need to know. Is incorrect because there is no such thing. The need to know is indicated by the catergories the object belongs to. This is NOT the best answer.
Reference(s) used for this question:
OIG CBK, Access Control (pages 186 - 188)
AIO, 3rd Edition, Access Control (pages 162 - 163)
AIO, 4th Edittion, Access Control, pp 212-214.
Wikipedia - http://en.wikipedia.org/wiki/Mandatory_Access_Control

Answer : D

Explanation: Both are the components of a sensitivity label.
The following are incorrect:
A Classification Set and a single Compartment. Is incorrect because the nomenclature
"Classification Set" is incorrect, there only one classifcation and it is not a "single compartment" but a Compartment Set.
A single classification and a single compartment. Is incorrect because while there only is one classifcation, it is not a "single compartment" but a Compartment Set.
A Classification Set and user credentials. Is incorrect because the nomenclature
"Classification Set" is incorrect, there only one classifcation and it is not "user credential" but a Compartment Set. The user would have their own sensitivity label.

Answer : D

Explanation: 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/c

Answer : C

Explanation: Kerberos depends on secret keys (symmetric ciphers). Kerberos is a third party authentication protocol. It was designed and developed in the mid 1980's by MIT. It is considered open source but is copyrighted and owned by MIT. It relies on the user's secret keys. The password is used to encrypt and decrypt the keys.
The following answers are incorrect:
It utilizes public key cryptography. Is incorrect because Kerberos depends on secret keys
(symmetric ciphers).
It encrypts data after a ticket is granted, but passwords are exchanged in plain text. Is incorrect because the passwords are not exchanged but used for encryption and decryption of the keys.
It is a second party authentication system. Is incorrect because Kerberos is a third party authentication system, you authenticate to the third party (Kerberos) and not the system you are accessing.
References:
MIT http://web.mit.edu/kerberos/
Wikipedi http://en.wikipedia.org/wiki/Kerberos_%28protocol%29
OIG CBK Access Control (pages 181 - 184)
AIOv3 Access Control (pages 151 - 155)