Explanation/Reference:
A certification authority (CA) is a third party entity that issues digital certificates (especially X.509 certificates) and vouches for the binding between the data items in a certificate. An issuing authority could be considered a correct answer, but not the best answer, since it is too generic.
Source: SHIREY, Robert W., RFC2828: Internet Security Glossary, may 2000.

The Data/Information Owner is ultimately responsible for the protection of the data. It is the Data/Information Owner that decides upon the classifications of that data they are responsible for.
The data owner decides upon the classification of the data he is responsible for and alters
that classification if the business need arises.
The following answers are incorrect:
Security Administrator. Is incorrect because this individual is responsible for ensuring that
the access right granted are correct and support the polices and directives that the
Data/Information Owner defines.
User. Is Incorrect because the user uses/access the data according to how the
Data/Information Owner defined their access.
Auditor. Is incorrect because the Auditor is responsible for ensuring that the access levels
are appropriate. The Auditor would verify that the Owner classified the data properly.
References:
CISSP All In One Third Edition, Shon Harris, Page 121

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 Clark-Wilson 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.
Clark-Wilson 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 Clark-Wilson 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.
References:
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

Section: Network and Telecommunications

Section: Cryptography
Explanation/Reference:
In a known plaintext attack, the attacker has the plaintext and ciphertext of one or more messages. The goal is to discover the key used to encrypt the messages so that other messages can be deciphered and read.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 3rd Ed., chapter 8:
Cryptography (page 676). Also check out: Handbook of Applied Cryptography 4th Edition by Alfred J.
Menezes, Paul C. van Oorschot and Scott A. Vanstone.