SSCP Exam Questions and Answers | Exam-Dumps (Page: 27)

QUESTION: 133 Topic: 1, Access Control

Which security model introduces access to objects only through programs?

The Biba model
The Bell-LaPadula model
The Clark-Wilson model
The information flow model

Answer(s): C

Explanation:

In the Clark-Wilson model, the subject no longer has direct access to objects but instead must access them through programs (well -formed transactions). The ClarkWilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system.
The model is primarily concerned with formalizing the notion of information integrity. Information
integrity is maintained by preventing corruption of data items in a system due to either error or malicious intent. An integrity policy describes how the data items in the system should be kept valid from one state of the system to the next and specifies the capabilities of various principals in the system. The model defines enforcement rules and certification rules.
ClarkWilson is more clearly applicable to business and industry processes in which the integrity of the information content is paramount at any level of classification.
Integrity goals of ClarkWilson model:
Prevent unauthorized users from making modification (Only this one is addressed by the Biba model).
Separation of duties prevents authorized users from making improper modifications. Well formed transactions: maintain internal and external consistency i.e. it is a series of operations that are carried out to transfer the data from one consistent state to the other.
The following are incorrect answers:
The Biba model is incorrect. The Biba model is concerned with integrity and controls access to objects based on a comparison of the security level of the subject to that of the object.
The Bell-LaPdaula model is incorrect. The Bell-LaPaula model is concerned with confidentiality and controls access to objects based on a comparison of the clearence level of the subject to the classification level of the object.
The information flow model is incorrect. The information flow model uses a lattice where objects are labelled with security classes and information can flow either upward or at the same level. It is similar in framework to the Bell-LaPadula model.

Reference:

ISC2 Official Study Guide, Pages 325 - 327
AIO3, pp. 284 - 287
AIOv4 Security Architecture and Design (pages 338 - 342) AIOv5 Security Architecture and Design (pages 341 - 344) Wikipedia at: https://en.wikipedia.org/wiki/Clark-Wilson_model

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QUESTION: 134 Topic: 1, Access Control

Which security model ensures that actions that take place at a higher security level do not affect actions that take place at a lower level?

The Bell-LaPadula model
The information flow model
The noninterference model
The Clark-Wilson model

Answer(s): C

Explanation:

The goal of a noninterference model is to strictly separate differing security levels to assure that higher-level actions do not determine what lower-level users can see. This is in contrast to other security models that control information flows between differing levels of users, By maintaining strict separation of security levels, a noninterference model minimizes leakages that might happen through a covert channel.
The model ensures that any actions that take place at a higher security level do not affect, or interfere with, actions that take place at a lower level. It is not concerned with the flow of data, but rather with what a subject knows about the state of the system. So if an entity at a higher security level performs an action, it can not change the state for the entity at the lower level.
The model also addresses the inference attack that occurs when some one has access to some type of information and can infer(guess) something that he does not have the clearance level or authority to know.
The following are incorrect answers:
The Bell-LaPadula model is incorrect. The Bell-LaPadula model is concerned only with confidentiality and bases access control decisions on the classfication of objects and the clearences of subjects.
The information flow model is incorrect. The information flow models have a similar framework to the Bell-LaPadula model and control how information may flow between objects based on security classes. Information will be allowed to flow only in accordance with the security policy.
The Clark-Wilson model is incorrect. The Clark-Wilson model is concerned with change control and assuring that all modifications to objects preserve integrity by means of well-formed transactions and usage of an access triple (subjet - interface - object).

Reference:

CBK, pp 325 - 326
AIO3, pp. 290 - 291
AIOv4 Security Architecture and Design (page 345)
AIOv5 Security Architecture and Design (pages 347 - 348) https://en.wikibooks.org/wiki/Security_Architecture_and_Design/Security_Models#Noninterference _Models

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QUESTION: 135 Topic: 1, Access Control

Which of the following security models does NOT concern itself with the flow of data?

The information flow model
The Biba model
The Bell-LaPadula model
The noninterference model

Answer(s): D

Explanation:

The goal of a noninterference model is to strictly separate differing security levels to assure that higher-level actions do not determine what lower-level users can see. This is in contrast to other security models that control information flows between differing levels of users, By maintaining strict separation of security levels, a noninterference model minimizes leakages that might happen through a covert channel.
The Bell-LaPadula model is incorrect. The Bell-LaPadula model is concerned with confidentiality and bases access control decsions on the classfication of objects and the clearences of subjects.
The information flow model is incorrect. The information flow models have a similar framework to the Bell-LaPadula model and control how information may flow between objects based on security classes.
The Biba model is incorrect. The Biba model is concerned with integrity and is a complement to the Bell-LaPadula model in that higher levels of integrity are more trusted than lower levels. Access control us based on these integrity levels to assure that read/write operations do not decrease an object's integrity.

Reference:

CBK, pp 325 - 326
AIO3, pp. 290 - 291

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QUESTION: 136 Topic: 1, Access Control

What Orange Book security rating is reserved for systems that have been evaluated but fail to meet the criteria and requirements of the higher divisions?

A
D
E
F

Answer(s): B

Explanation:

D or "minimal protection" is reserved for systems that were evaluated under the TCSEC but did not meet the requirements for a higher trust level.
A is incorrect. A or "Verified Protectection" is the highest trust level under the TCSEC. E is incorrect. The trust levels are A - D so "E" is not a valid trust level. F is incorrect. The trust levels are A - D so "F" is not a valid trust level.
CBK, pp. 329 - 330
AIO3, pp. 302 - 306

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QUESTION: 137 Topic: 1, Access Control

Which division of the Orange Book deals with discretionary protection (need-to-know)?

D
C
B
A

Answer(s): B

Explanation:

C deals with discretionary protection. See matric below:

TCSEC Matric
The following are incorrect answers:
D is incorrect. D deals with minimal security.
B is incorrect. B deals with mandatory protection.
A is incorrect. A deals with verified protection.

Reference:

CBK, p. 329 330
and
Shon Harris, CISSP All In One (AIO), 6th Edition , page 392-393

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ISC SSCP Exam (page: 27) ISC SSCP System Security Certified Practitioner (SSCP) Updated on: 25-Dec-2025

QUESTION: 133 Topic: 1, Access Control

Explanation:

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QUESTION: 134 Topic: 1, Access Control

Explanation:

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QUESTION: 135 Topic: 1, Access Control

Explanation:

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QUESTION: 136 Topic: 1, Access Control

Explanation:

QUESTION: 137 Topic: 1, Access Control

Explanation:

Reference:

ISC SSCP Exam (page: 27)
ISC SSCP System Security Certified Practitioner (SSCP)
Updated on: 25-Dec-2025