ISC2 CERTIFIED IN CYBERSECURITY CC
PRACTICE COMPREHENSIVE REVIEW 2026
QUESTIONS WITH ANSWERS GRADED A+
⩥ Asymmetric Encryption. Answer: An algorithm that uses one key to
encrypt and a different key to decrypt the input plaintext.
⩥ Checksum. Answer: A digit representing the sum of the correct digits
in a piece of stored or transmitted digital data, against which later
comparisons can be made to detect errors in the data.
⩥ Ciphertext. Answer: The altered form of a plaintext message so it is
unreadable for anyone except the intended recipients. In other words, it
has been turned into a secret.
⩥ Classification. Answer: Classification identifies the degree of harm to
the organization, its stakeholders or others that might result if an
information asset is divulged to an unauthorized person, process or
organization. In short, classification is focused first and foremost on
maintaining the confidentiality of the data, based on the data sensitivity.
⩥ Configuration management. Answer: A process and discipline used to
ensure that the only changes made to a system are those that have been
authorized and validated.
,⩥ Cryptanalyst. Answer: One who performs cryptanalysis which is the
study of mathematical techniques for attempting to defeat cryptographic
techniques and/or information systems security. This includes the
process of looking for errors or weaknesses in the implementation of an
algorithm or of the algorithm itself.
⩥ Cryptography. Answer: The study or applications of methods to secure
or protect the meaning and content of messages, files, or other
information, usually by disguise, obscuration, or other transformations
of that content and meaning.
⩥ Data Loss Prevention (DLP). Answer: System capabilities designed to
detect and prevent the unauthorized use and transmission of information.
⩥ Decryption. Answer: The reverse process from encryption. It is the
process of converting a ciphertext message back into plaintext through
the use of the cryptographic algorithm and the appropriate key for
decryption (which is the same for symmetric encryption, but different
for asymmetric encryption). This term is also used interchangeably with
the "deciphering."
⩥ Degaussing. Answer: A technique of erasing data on disk or tape
(including video tapes) that, when performed properly, ensures that there
is insufficient magnetic remanence to reconstruct data.
,⩥ Digital Signature. Answer: The result of a cryptographic
transformation of data which, when properly implemented, provides the
services of origin authentication, data integrity, and signer non-
repudiation. NIST SP 800-12 Rev. 1
⩥ Egress Monitoring. Answer: Monitoring of outgoing network traffic.
⩥ Encryption. Answer: The process and act of converting the message
from its plaintext to ciphertext. Sometimes it is also referred to as
enciphering. The two terms are sometimes used interchangeably in
literature and have similar meanings.
⩥ Encryption System. Answer: The total set of algorithms, processes,
hardware, software, and procedures that taken together provide an
encryption and decryption capability.
⩥ Hardening. Answer: A reference to the process of applying secure
configurations (to reduce the attack surface) and locking down various
hardware, communications systems, and software, including operating
system, web server, application server, application, etc. Hardening is
normally performed based on industry guidelines and benchmarks, such
as those provided by the Center for Internet Security (CIS).
⩥ Hash Function. Answer: An algorithm that computes a numerical
value (called the hash value) on a data file or electronic message that is
used to represent that file or message and depends on the entire contents
, of the file or message. A hash function can be considered to be a
fingerprint of the file or message. NIST SP 800-152
⩥ Hashing. Answer: The process of using a mathematical algorithm
against data to produce a numeric value that is representative of that
data. Source CNSSI 4009-2015
⩥ Information Sharing. Answer: The requirements for information
sharing by an IT system with one or more other IT systems or
applications, for information sharing to support multiple internal or
external organizations, missions, or public programs. NIST SP 800-16
⩥ Ingress Monitoring. Answer: Monitoring of incoming network traffic.
⩥ Message Digest. Answer: A digital signature that uniquely identifies
data and has the property such that changing a single bit in the data will
cause a completely different message digest to be generated. NISTIR-
8011 Vol.3
⩥ Operating System. Answer: The software "master control application"
that runs the computer. It is the first program loaded when the computer
is turned on, and its main component, the kernel, resides in memory at
all times. The operating system sets the standards for all application
programs (such as the Web server) that run in the computer. The
applications communicate with the operating system for most user
interface and file management operations. NIST SP 800-44 Version 2
PRACTICE COMPREHENSIVE REVIEW 2026
QUESTIONS WITH ANSWERS GRADED A+
⩥ Asymmetric Encryption. Answer: An algorithm that uses one key to
encrypt and a different key to decrypt the input plaintext.
⩥ Checksum. Answer: A digit representing the sum of the correct digits
in a piece of stored or transmitted digital data, against which later
comparisons can be made to detect errors in the data.
⩥ Ciphertext. Answer: The altered form of a plaintext message so it is
unreadable for anyone except the intended recipients. In other words, it
has been turned into a secret.
⩥ Classification. Answer: Classification identifies the degree of harm to
the organization, its stakeholders or others that might result if an
information asset is divulged to an unauthorized person, process or
organization. In short, classification is focused first and foremost on
maintaining the confidentiality of the data, based on the data sensitivity.
⩥ Configuration management. Answer: A process and discipline used to
ensure that the only changes made to a system are those that have been
authorized and validated.
,⩥ Cryptanalyst. Answer: One who performs cryptanalysis which is the
study of mathematical techniques for attempting to defeat cryptographic
techniques and/or information systems security. This includes the
process of looking for errors or weaknesses in the implementation of an
algorithm or of the algorithm itself.
⩥ Cryptography. Answer: The study or applications of methods to secure
or protect the meaning and content of messages, files, or other
information, usually by disguise, obscuration, or other transformations
of that content and meaning.
⩥ Data Loss Prevention (DLP). Answer: System capabilities designed to
detect and prevent the unauthorized use and transmission of information.
⩥ Decryption. Answer: The reverse process from encryption. It is the
process of converting a ciphertext message back into plaintext through
the use of the cryptographic algorithm and the appropriate key for
decryption (which is the same for symmetric encryption, but different
for asymmetric encryption). This term is also used interchangeably with
the "deciphering."
⩥ Degaussing. Answer: A technique of erasing data on disk or tape
(including video tapes) that, when performed properly, ensures that there
is insufficient magnetic remanence to reconstruct data.
,⩥ Digital Signature. Answer: The result of a cryptographic
transformation of data which, when properly implemented, provides the
services of origin authentication, data integrity, and signer non-
repudiation. NIST SP 800-12 Rev. 1
⩥ Egress Monitoring. Answer: Monitoring of outgoing network traffic.
⩥ Encryption. Answer: The process and act of converting the message
from its plaintext to ciphertext. Sometimes it is also referred to as
enciphering. The two terms are sometimes used interchangeably in
literature and have similar meanings.
⩥ Encryption System. Answer: The total set of algorithms, processes,
hardware, software, and procedures that taken together provide an
encryption and decryption capability.
⩥ Hardening. Answer: A reference to the process of applying secure
configurations (to reduce the attack surface) and locking down various
hardware, communications systems, and software, including operating
system, web server, application server, application, etc. Hardening is
normally performed based on industry guidelines and benchmarks, such
as those provided by the Center for Internet Security (CIS).
⩥ Hash Function. Answer: An algorithm that computes a numerical
value (called the hash value) on a data file or electronic message that is
used to represent that file or message and depends on the entire contents
, of the file or message. A hash function can be considered to be a
fingerprint of the file or message. NIST SP 800-152
⩥ Hashing. Answer: The process of using a mathematical algorithm
against data to produce a numeric value that is representative of that
data. Source CNSSI 4009-2015
⩥ Information Sharing. Answer: The requirements for information
sharing by an IT system with one or more other IT systems or
applications, for information sharing to support multiple internal or
external organizations, missions, or public programs. NIST SP 800-16
⩥ Ingress Monitoring. Answer: Monitoring of incoming network traffic.
⩥ Message Digest. Answer: A digital signature that uniquely identifies
data and has the property such that changing a single bit in the data will
cause a completely different message digest to be generated. NISTIR-
8011 Vol.3
⩥ Operating System. Answer: The software "master control application"
that runs the computer. It is the first program loaded when the computer
is turned on, and its main component, the kernel, resides in memory at
all times. The operating system sets the standards for all application
programs (such as the Web server) that run in the computer. The
applications communicate with the operating system for most user
interface and file management operations. NIST SP 800-44 Version 2
