〇：Keys are generated from a master key.

To generate a composite key, a master key is created and a symmetric key (subkey) is generated. The key derivation function generates the encryption key from the secret value. The secret value can be a master key, passphrase, or password. The key derivation function (KDF) generates a key for symmetric key ciphers from a given password.

×：Session keys are generated from each other.

Session keys are generated from each other, not from the master key, which is incorrect.

×：Asymmetric ciphers are used to encrypt symmetric keys.

It is incorrect because key encryption is not even related to the key derivation function (KDF).

×：The master key is generated from the session key.

Reverse, incorrect. Session keys are generally generated from master keys.

〇：Zero Knowledge Proof

Zero Knowledge Proof means that someone can tell you something without telling you more information than you need to know. In cryptography, it means proving that you have a certain key without sharing that key or showing it to anyone. Zero knowledge proof (usually mathematical) is an interactive way for one party to prove to another that something is true without revealing anything sensitive.

×：Key Clustering

Key clustering is the phenomenon of encrypting the same plaintext with different keys, but with the same ciphertext.

×：Avoiding Birthday Attacks

An attacker can attempt to force a collision, called a birthday attack. This attack is based on the mathematical birthday paradox present in standard statistics. This is a cryptographic attack that uses probability theory to exploit the mathematics behind the birthday problem.

×：Provides data confidentiality

Provided via encryption when data is encrypted with a key, which is incorrect.

〇：Execution Domain Switching

Execution domain switching occurs when the CPU needs to move between executing instructions for a more trusted process versus a less trusted process. Trusted Computing Base (TCB) allows processes to switch domains in a secure manner to access different levels of information based on sensitivity. Execution domain switching occurs when a process needs to invoke a process in a higher protection ring. The CPU executes the user-mode instruction back into privileged mode.

At first glance, this is a geeky problem that does not make sense. But don’t give up. Since there is no such thing as skipping, you can only get a right or wrong answer when the question is posed, so it is preferable to answer the question with some degree of prediction.

From this point on, let’s consider how to answer the questions. If you look at the question text and read it to the point where it reads, “You moved from one area to the other, and that was a security breach?” If you can read to that point, then you have two choices: deny or “stop the process,” or change or “switch the domain of execution. Next, the question text reads “if you need to access it,” which is asking how to accomplish this objective, not whether or not you should.

×：Execution of I/O operations

This is incorrect because input/output (I/O) operations are not initiated to ensure security when a process in one domain needs to access another domain in order to retrieve sensitive information. I/O operations are performed when input devices (such as a mouse or keyboard) and output devices (such as a monitor or printer, etc.) interact with an application or applications.

×：Stopping a Process

A process deactivation is one that occurs when a process instruction is fully executed by the CPU or when another process with a higher priority calls the CPU, which is incorrect. When a process is deactivated, new information about the new requesting process must be written to a register in the CPU. The TCB component must ensure that this is done, since the data replaced in the registers may be confidential.

×：Mapping from virtual memory to real memory

Incorrect because memory mapping occurs when a process needs its instructions and data processed by the CPU. The memory manager maps logical addresses to physical addresses so that the CPU knows where to place the data. This is the responsibility of the operating system’s memory manager.

The Kerckhoffs’s principle is the idea that cryptography should be secure even if everything but the private key is known. When encrypting data, one decides on a private key and how to encrypt it using that private key. Kerckhoffs says that even if it is known how it is encrypted, it should not be deciphered as long as the secret key is not discovered. Encryption has been with the history of human warfare. The main purpose is to communicate a strategy to one’s allies without being discovered by the enemy. In battle, its designs and encryption devices may be stolen by spies. Therefore, the encryption must be such that it cannot be solved without the key, no matter how much is known about how it works.

〇：The most common method used is to change the most significant bit.

Steganography is a method of hiding data in other media types. One of the most common ways to embed messages in some types of media is using the least significant bit (LSB). This is because many types of files are modified and this is where sensitive data can be made visible and hidden without modifying the file. the LSB approach has been successful in hiding information within the graphics of high-resolution or sound-heavy audio files (high bit rate).

×：Hiding by abstraction.

Steganography is incorrect because it is concealment by abstraction. Security by obscurity means that someone uses secrecy as a way to protect an asset, rather than actually using the measure to secure something.

×：Just as encryption does, steganography is not a front for the existence of the sensitive data itself.

It is true that steganography does not draw attention to itself as does encryption. In other words, it is concealment by abstraction.

×：Media files are ideal for steganographic transmissions that are large in size.

This is incorrect because it is true that larger media files are ideal for steganographic transmissions because everyone needs to privately use multiple bits to manipulate with low likelihood of noticing.

〇：OCSP is a protocol developed specifically to check CRLs during the certificate validation process.

A Certificate Authority (CA) is responsible for creating certificates, maintaining and distributing them, and revoking them when necessary. Revocation is handled by the CA and the revoked certificate information is stored in a Certificate Revocation List (CRL). This is a list of all revoked certificates. This list is maintained and updated periodically. A certificate is revoked if the key owner’s private key has been compromised, if the CA has been compromised, or if the certificate is incorrect. If a certificate is revoked for any reason, the CRL is a mechanism for others to inform you of this information. The Online Certificate Status Protocol (OCSP) uses this CRL; when using CRLs, the user’s browser must examine the CRL value to the client to see if the accreditation has been revoked or the CA is constantly checking to make sure they have an updated CRL. If OCSP is implemented, it will do this automatically in the background. It performs real-time verification of the certificate and reports back to the user whether the certificate is valid, invalid, or unknown.

×：CRL was developed as a more efficient approach to OCSP.

CRLs are often incorrect because they are a cumbersome approach; OCSP is used to deal with this tediousness; OCSP does this work in the background when using CRLs; OCSP checks the CRL to see if the certificate has been revoked by Checks.

×：OCSP is a protocol for submitting revoked certificates to CRLs.

OCSP is incorrect because it does not submit revoked certificates to the CRL; the CA is responsible for certificate creation, distribution, and maintenance.

×：CRL provides real-time validation of certificates and reports to OCSP.

Incorrect because CRL does not provide real-time validation of certificates to OCSP.

〇：Public key infrastructure is a mechanism configuration for public key cryptographic distribution, and public key cryptography is another name for asymmetric encryption.

Public key cryptography is asymmetric cryptography. The terms are used interchangeably. Public key cryptography is a concept within the Public Key Infrastructure (PKI), which consists of various parts such as Certificate Authorities, Registration Authorities, certificates, keys, programs, and users. Public Key Infrastructure is used to identify and create users, distribute and maintain certificates, revoke and distribute certificates, maintain encryption keys, and for the purpose of encrypted communication and authentication.

×：Public key infrastructure uses symmetric algorithms and public key cryptography uses asymmetric algorithms.

This is incorrect because the public key infrastructure uses a hybrid system of symmetric and asymmetric key algorithms and methods. Public key cryptography is to use asymmetric algorithms. Therefore, asymmetric and public key cryptography are interchangeable, meaning they are the same. Examples of asymmetric algorithms are RSA, elliptic curve cryptography (ECC), Diffie-Hellman, and El Gamal.

×：Public key infrastructure is used to perform key exchange, while public key cryptography is used to create public/private key pairs.

This is incorrect because public key cryptography is the use of asymmetric algorithms used to create public/private key pairs, perform key exchange, and generate and verify digital signatures.

×：Public key infrastructure provides confidentiality and integrity, while public key cryptography provides authentication and non-repudiation.

Incorrect because the public key infrastructure itself does not provide authentication, non-repudiation, confidentiality, or integrity.

〇：Digital Signature

A digital signature is a hash value encrypted with the sender’s private key. The act of signing means encrypting a hash value of a message with a private key. A message can be digitally signed, providing authentication, non-repudiation, and integrity. The hash function guarantees the integrity of the message, and the signature of the hash value provides authentication and non-repudiation.

×：Encryption Algorithms

Encryption algorithms are wrong because they provide confidentiality. Encryption is most commonly performed using symmetric algorithms. Symmetric algorithms can provide authentication, non-repudiation, and integrity as well as confidentiality.

×：Hash Algorithms

Hash algorithms are wrong because they provide data integrity. Hash algorithms generate a message digest, which detects whether modifications have been made (also called a hash value). The sender and receiver individually generate their own digests, and the receiver compares these values. If they differ, the receiver can know the message has been modified. Hash algorithms cannot provide authentication or non-repudiation.

×：Encryption paired with digital signatures

This is incorrect because encryption and digital signatures provide confidentiality, authentication, non-repudiation, and integrity. Encryption alone provides confidentiality. And digital signatures provide authentication, non-repudiation, and integrity. The question requires that it can provide authentication, non-repudiation, and integrity. It is a nasty question.

〇：The sender encrypts the message digest with his/her private key.

A digital signature is a hash value encrypted with the sender’s private key. The act of digitally signing means encrypting the hash value of the message with his/her private key. The sender would encrypt that hash value using her private key. When the recipient receives the message, she performs a hash function on the message and generates the hash value herself. She then decrypts the hash value (digital signature) sent with the sender’s public key. The receiver compares the two values and, if they are the same, can verify that the message was not altered during transmission.

×：The sender encrypts the message digest with his/her public key.

The sender is wrong because if the message encrypts the digest with his/her public key, the recipient cannot decrypt it. The recipient needs access to the sender’s private key, which must not occur. The private key must always be kept secret.

×：The receiver encrypts the message digest with his/her private key.

The receiver is wrong because the message must decrypt the digest with the sender’s public key. The message digest is encrypted with the sender’s private key, which can only be decrypted with the sender’s public key.

×：The receiver encrypts the message digest with his/her public key.

The receiver is wrong because the message must decrypt the digest with the sender’s public key. The message digest is encrypted with the sender’s private key, which can only be decrypted with the sender’s public key.

〇：The client generates a session key and encrypts it with a public key.

Transport Layer Security (TLS) uses public key cryptography to provide data encryption, server authentication, message integrity, and optionally client authentication. When a client accesses a cryptographically protected page, the web server initiates TLS and begins the process of securing subsequent communications. The server performs a three-handshake to establish a secure session. After that, client authentication with a digital certificate, as the case may be, comes in. The client then generates a session key, encrypts it with the server’s public key, and shares it. This session key is used as the symmetric key for encrypting the data to be transmitted thereafter. Thus, the correct answer is: “The client generates a session key and encrypts it with the public key.” will be

×：The server generates the session key and encrypts it with the public key.

The server does not encrypt with the public key.

×：The server generates a session key and encrypts it with the private key.

Even if encryption is performed from the server side, it can be decrypted with the public key, so it is not structurally possible.

×：The client generates a session key and encrypts it with its private key.

The client side does not have the private key.

〇：One-time pad

Stream ciphers refer to one-time pad technology. In practice, stream ciphers cannot provide the level of protection that one-time pads do, but are practical.

×：AES

AES is incorrect because it is a symmetric block cipher. When a block cipher is used for encryption and decryption purposes, the message is divided into blocks of bits.

×：Block ciphers

Block ciphers are used for encryption and decryption purposes. The message is wrong because it is divided into blocks of bits.

×：RSA

RSA is incorrect because it is an asymmetric algorithm.

〇：TOGAF

The Open Group Architecture Framework (TOGAF) is a vendor-independent platform for the development and implementation of enterprise architecture. It focuses on the effective management of enterprise data using metamodels and service-oriented architectures (SOA). Proficient implementations of TOGAF aim to reduce fragmentation caused by inconsistencies between traditional IT systems and actual business processes. It also coordinates new changes and functionality so that new changes can be easily integrated into the enterprise platform.

×：Department of Defense Architecture Framework (DoDAF)

In accordance with the guidelines for the organization of the enterprise architecture of the U.S. Department of Defense systems, this is incorrect. It is also suitable for large, complex integrated systems in the military, civilian, and public sectors.

×：Capability Maturity Model Integration (CMMI) during software development.

It is inappropriate because it is a framework for the purpose of designing and further improving software. CMMI provides a standard for software development processes that can measure the maturity of the development process.

×：ISO/IEC 42010

Incorrect because it consists of recommended practices to simplify the design and conception of software-intensive system architectures. This standard provides a kind of language (terminology) to describe the different components of software architecture and how to integrate it into the development life cycle.

〇：CA signs certificates.

A Certificate Authority (CA) is a trusted agency (or server) that maintains digital certificates. When a certificate is requested, the Registration Authority (RA) verifies the identity of the individual and passes the certificate request to the CA The CA creates the certificate, signs it, and maintains the certificate over its lifetime.

×：RA creates the certificate and CA signs it.

Incorrect because the RA does not create the certificate; the CA creates it and signs it; the RA performs authentication and registration tasks; establishes the RA, verifies the identity of the individual requesting the certificate, initiates the authentication process to the CA on behalf of the end user, and performs certificate life cycle RAs cannot issue certificates, but can act as a broker between the user and the CA When a user needs a new certificate, they make a request to the RA and the RA goes to the CA to verify all necessary identification before granting the request The RA verifies all necessary identification information before granting the request.

×：RA signs certificates.

The RA signs the certificate, which is incorrect because the RA does not sign the certificate; the CA signs the certificate; the RA verifies the user’s identifying information and then sends the certificate request to the CA.

×：The user signs the certificate.

Incorrect because the user has not signed the certificate; in a PKI environment, the user’s certificate is created and signed by the CA. The CA is a trusted third party that generates the user certificate holding its public key.

A key escrow system is one in which a third-party organization holds a copy of the public/private key pair. If the private key is stolen, all ciphers can be decrypted. Conversely, if it is lost, all ciphers cannot be decrypted. Therefore, you want to have a copy. However, if you have it yourself, it may be stolen if a break-in occurs, so you leave it with a third-party organization.

〇：Conflict condition

A race condition is present when a process performs a task on a shared resource and the sequence could be in the wrong order. 2 or more processes can have a race condition if they use a shared resource, like data in a variable. It is important that processes perform their functions in the correct sequence.

×：Backdoors

Backdoors are incorrect because they are “listening” services on certain ports. Backdoors are implemented by attackers to allow easy access to the system without authenticating as a normal system user.

×：Maintenance Hooks

Maintenance hooks are specific software codes that allow easy and unauthorized access to sensitive parts of a software product. Software programmers use maintenance hooks to allow them to get quick access to the code so that they can make fixes in immediate, but this is dangerous.

×：Data validation errors

Data validation errors are wrong because an attacker cannot operate on the process execution sequence.

〇：Operating system patching is easier.

This is an incorrect choice question. Virtualization does not simplify operating system patching. In fact, it complicates it by adding at least one additional operating system. Each operating system differs from the typical version configuration, adding to the complexity of patching. The server’s own operating system runs as a guest within the host environment. In addition to patching and maintaining the traditional server operating system, the virtualization software itself must be patched and maintained.

For this question, we do not require an understanding of all the technical systems of virtualization. What is required here is a selection of answers based on a process of elimination.

×：I can build a secure computing platform.

Building a secure computing platform may not be a feature of virtualization per se. However, can we build a secure environment? This is not a false choice because it cannot be ruled out.

×：It can provide fault and error containment.

Virtualization can be host independent. In terms of containment, it can be interpreted as being able to provide fault and error containment through independence from physical servers. Therefore, it cannot be denied and is therefore not an incorrect choice.

×：It can provide powerful debugging capabilities.

Virtualization can reproduce a unique environment, not just put up a clean virtual host. Therefore, it is undeniable and therefore out of the wrong choice.

〇：Common Criteria

Common Criteria was created in the early 1990s as a way to combine the strengths of both the Trustworthy Computer Systems Evaluation Criteria (TCSEC) and the Information Technology Security Evaluation Criteria (ITSEC) and eliminate their weaknesses. Common Criteria is more flexible than TCSEC and easier than ITSEC. Common Criteria is recognized worldwide and assists consumers by reducing the complexity of assessments and eliminating the need to understand the definitions and meanings of different assessments in different assessment schemes. This also helps manufacturers because they can now build a specific set of requirements when they want to market their products internationally, rather than having to meet several different evaluation criteria under different rules and requirements.

×：ITSEC

This is incorrect because it is not the most widely used information technology security evaluation standard. ITSEC was the first attempt to establish a single standard for evaluating the security attributes of computer systems and products in many European countries. In addition, ITSEC separates functionality and assurance in its evaluations, giving each a separate rating. It was developed to provide greater flexibility than TCSEC and addresses integrity, availability, and confidentiality in networked systems. The goal of ITSEC was to become the global standard for product evaluation, but it failed to achieve that goal and was replaced by Common Criteria.

×：Red Book

Wrong, as it is a U.S. government publication that addresses the topic of security evaluation of networks and network components. Formally titled Trusted Network Interpretation, it provides a framework for protecting different types of networks. Subjects accessing objects on the network must be controlled, monitored, and audited.

×：Orange Book

Incorrect as this is a U.S. Government publication that addresses government and military requirements and expectations for operating systems. The Orange Book is used to evaluate whether a product is suitable for the security characteristics and specific applications or functions required by the vendor. The Orange Book is used to review the functionality, effectiveness, and assurance of the product under evaluation, using classes designed to address typical patterns of security requirements. It provides a broad framework for building and evaluating trusted systems, with an emphasis on controlling which users have access to the system. We call it the Orange Book, but another name for it is Trusted Computer System Evaluation Criteria (TCSEC).

〇：Zachman Framework

The Zachman Framework is an enterprise architecture that determines the what, how, where, who, when, and why for each mandate. Enterprise architecture is to create a management structure to achieve business goals. We create an organization to achieve business goals, and basically, the larger the business goals, the larger the organization. If the structure of the organization is not in place, the organization will not run efficiently, as there may be residual work that needs to be done, or there may be friction between jobs due to authority that is covered by others. Therefore, it is necessary to clarify the scope of each job authority in order to put the organization in order. The job authority here is different from the perspectives of human resources or sales. It is easier to think of them as hierarchically separated to achieve business goals. Clarify the scope in Executive, Business Management, Architecture, Engineers, Subcontractors, and Stakeholders, respectively. Therefore, the correct answer is the Zachman Framework.

×：SABSA

SABSA (Sherwood Applied Business Security Architecture) is a framework to ensure that security measures are working properly in achieving business goals. Unlike the Zachman Framework, the tasks to be organized are hierarchical elements. Business Requirements > Conceptual Architecture > Logical Service Architecture > Physical Infrastructure Architecture > Technology and Products, each with a 5W1H practice.

×：Five-W method

There is no such term. If there is, it is a term coined to make it easier to interpret.

×：Biba Model

The Biba model is a security model that indicates that data cannot be changed without permission.

〇：Primary entry doors should have controlled access via swipe card or cryptographic locks. Secondary doors should not be secured from the inside and allowed entry. 

Data centers, server rooms, and wiring closets should be located in the core areas of the facility, near wiring distribution centers. Strict access control mechanisms and procedures should be implemented for these areas. Access control mechanisms can lock smart card readers, biometric readers, or a combination of these. These restricted areas should have only one access door, but fire code requirements typically dictate that there must be at least two doors in most data centers and server rooms. Only one door should be used for daily entry and exit and the other door should be used only in case of an emergency, i.e., if a fire breaks out in a data center or server room, the door should be locked. This second door should not be an access door, meaning people should not be able to come through this door. It should be locked, but should have a panic bar that will release the lock if it is used as an exit, pushed from the inside.

×：The primary and secondary entry doors must have control access via swipe cards or cryptographic locks.  

This is incorrect because even two entry doors should not be allowed to pass through with the identification, authentication, and authorization process. There should only be one entry point into the server room. No other door should provide an entry point, but can be used for an emergency exit. Therefore, secondary doors should be protected from the inside to prevent intrusion.

×：The primary entry door should have controlled access via a guard. Two doors should not be secured from the inside and allowed entry.

The main entry door to the server room is incorrect as it requires an identification, authentication, and authorization process to be performed. Swipe cards and cryptographic locks perform these functions. Server rooms should ideally not be directly accessible from public areas such as stairways, hallways, loading docks, elevators, and restrooms. This helps prevent foot traffic from casual passersby. Those who are by the door to the area to be secured should have a legitimate reason for being there, as opposed to those on the way to the meeting room, for example.

×：The main entry door must have controlled access via swipe card or crypto lock. Two doors must have security guards.  

Two doors should not have security guards, because it is wrong. The door should be protected from the inside simply so it cannot be used as an entry. Two-door must function as an emergency exit.