〇：* (star) Integrity Property

The Biba model defines a model with completeness as having two axioms. The * (star) Integrity Property is that the subordinate’s document is to be seen and there is no Read Down. The * (star) Integrity Property is that there is no Write Up, that is, no rewriting of the supervisor’s document. If the Simple Integrity Axiom is not followed, the subordinate’s document will be seen and may absorb unclassified and incorrect information at a lower level. If the * (star) Integrity Property is not followed, a supervisor’s document will be rewritten, which will release incorrect information to the supervisor who sees it. Therefore, both are integrity conditions.

×：Simple Integrity Property

The Simple Integrity Property is a constraint on Read Down.

×：Strong Tranquillity Axiom

The Strong Tranquillity Axiom is the constraint not to change permissions while the system is running.

×：Weak Tranquillity Axiom

Weak Tranquillity Axiom means do not change privileges until the attribute is inconsistent.

〇：Keys will need to be distributed via a secure transmission channel.

For two users to exchange messages encrypted with a symmetric algorithm, they need to figure out how to distribute the key first. If the key is compromised, all messages encrypted with that key can be decrypted and read by an intruder. Simply sending the key in an email message is not secure because the key is not protected and can easily be intercepted and used by an attacker.

×：Computation is more intensive than in asymmetric systems.

That is incorrect because it describes the advantages of symmetric algorithms. Symmetric algorithms tend to be very fast because they are less computationally intensive than asymmetric algorithms. They can encrypt and decrypt relatively quickly large amounts of data that take an unacceptable amount of time to encrypt and decrypt with asymmetric algorithms.

×：Much faster operation than asymmetric systems

Symmetric algorithms are faster than asymmetric systems, but this is an advantage. Therefore, it is incorrect.

×：Mathematically intensive tasks must be performed

Asymmetric algorithms are wrong because they perform a mathematically intensive task. Symmetric algorithms, on the other hand, perform relatively simple mathematical functions on bits during the encryption and decryption process.

〇：Graham-Denning Model

The Graham-Denning model addresses how access rights between subjects and objects are defined, developed, and integrated. It defines a basic set of rights in terms of the commands that a particular subject can execute on an object. The model has eight basic protective rights or rules on how to safely perform these types of functions

×：Brewer-Nash Model

It is incorrect because its purpose is to provide access control that can be changed dynamically according to the user’s previous actions. The main purpose is to protect against conflicts of interest due to user access attempts. For example, if a large marketing firm provides marketing promotions and materials for two banks, the employee responsible for the Bank A project should not be able to see information about Bank B, the marketing firm’s other bank customer. A conflict of interest could arise because the banks are competitors. If the project manager of the marketing firm’s Project A can see information about Bank B’s new marketing campaign, he may attempt to execute it rather than promote it to please more direct customers. Marketing firms have a bad reputation when internal employees can act irresponsibly.

×：Clark-Wilson Model

The Clark-Wilson model is incorrect because it is implemented to protect data integrity and ensure that transactions are properly formatted within the application. Subjects can only access objects through authorized programs. Segregation of duties is enforced. Auditing is required. The Clark-Wilson model addresses three integrity goals: preventing changes by unauthorized users, preventing inappropriate changes by unauthorized users, and maintaining internal and external consistency.

×：Bell-LaPadula Model

This model was developed to address concerns about the security of U.S. military systems and the leakage of classified information, and is incorrect. The primary goal of the model is to prevent unauthorized access to classified information. It is a state machine model that enforces the confidentiality aspect of access control. Matrices and security levels are used to determine if a subject has access to different objects. Specific rules are applied to control how objects interact with each other compared to the subject’s object classification.

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 security kernel implements and executes the reference monitor

The Trusted Computing Base (TCB) is a complete combination of protection mechanisms for a system. These are in the form of hardware, software, and firmware. These same components also comprise the security kernel. Reference monitors are access control concepts implemented and enforced by the security kernel via hardware, software, and firmware. In doing so, it ensures that the security kernel, the subject, has the proper permissions to access the object it is requesting. The subject, be it a program, user, or process, cannot access the requesting file, program, or resource until it is proven that it has the proper access rights.

×：The reference monitor is the core of the Trusted Computing Base (TCP), which is comprised of the security kernel.

This is incorrect because the reference monitor is not the core of the TCB. The core of the TCB is the security kernel, and the security kernel implements the concepts of the reference monitor. The reference monitor is a concept about access control. It is often referred to as an “abstract machine” because it is not a physical component.

×：The reference monitor implements and executes the security kernel.

The reference monitor does not implement and execute the security kernel, which is incorrect. On the contrary, the security kernel implements and executes the reference monitor. The reference monitor is an abstract concept, while the security kernel is a combination of hardware, software, and firmware in a trusted computing base.

×：The security kernel, i.e., the abstract machine, implements the concept of a reference monitor.

This is incorrect because abstract machine is not another name for security kernel. Abstract machine is another name for the reference monitor. This concept ensures that the abstract machine acts as an intermediary between the subject and the object, ensuring that the subject has the necessary rights to access the object it is requesting and protecting the subject from unauthorized access and modification. The security kernel functions to perform these activities.

〇：TOC/TOU

Certain attacks can take advantage of the way a system processes requests and performs tasks. A TOC/TOU attack handles a series of steps that the system uses to complete a task. This type of attack takes advantage of the reliance on the timing of events occurring in a multitasking operating system; TOC/TOU is a software vulnerability that allows the use of condition checking (i.e., credential verification) and the results from that condition checking function. In the scenario in this question, the fact that the web application is likely correctly configured indicates that the programming code of this application has this type of vulnerability embedded in the code itself.

×：Buffer overflow

When too much data is accepted as input to a particular process, a buffer overflow occurs. This is incorrect because it does not match the event in the problem statement. A buffer is an allocated segment of memory. A buffer can overflow arbitrarily with too much data, but to be used by an attacker, the code inserted into the buffer must be of a specific length and require a command to be executed by the attacker. These types of attacks are usually exceptional in that the fault is segmented, or sensitive data is provided to the attacker.

×：Blind SQL Injection

Blind SQL injection attacks are wrong because they are a type of SQL injection attack that sends true or false questions to the database. In a basic SQL injection, the attacker sends specific instructions in SQL format to query the associated database. In a blind SQL attack, the attacker is limited to sending a series of true-false questions to the database in order to analyze the database responses and gather sensitive information.

×：Cross Site Request Forgery (CSRF)

Cross Site Request Forgery (CSRF) is incorrect because it is an attack type that attempts to trick the victim into loading a web page containing malicious requests or operations. The attack operation is performed within the context of the victim’s access rights. The request inherits the victim’s identity and performs undesirable functions for the victim. In this type of attack, the attacker can cause the victim’s system to perform unintended actions such as changing account information, retrieving account data, or logging out. This type of attack could be related to the scenario described in this question, but focuses on how the user can bypass the locking mechanism built into the web application. The logic in the programming code is incorrectly developed and the locking function is bypassed because a rigorous series of checks and usage sequences are not performed correctly.

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.

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：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：Conduct a risk analysis.

The first step in the procedure described, which is the first step to be taken only to deploy an effective physical security program, is to conduct a risk analysis to identify vulnerabilities and threats and to calculate the business impact of each threat. The team presents the results of the risk analysis to management to define an acceptable risk level for the physical security program. From there, the team evaluates and determines if the baseline is met by implementation. Once the team identifies its responses and implements the measures, performance is continually evaluated. These performances will be compared to the established baselines. If the baseline is maintained on an ongoing basis, the security program is successful because it does not exceed the company’s acceptable risk level.

×：Create a performance metric for the countermeasure.  

The procedure to create a countermeasure performance metric is incorrect because it is not the first step in creating a physical security program. If monitored on a performance basis, it can be used to determine how beneficial and effective the program is. It allows management to make business decisions when investing in physical security protection for the organization. The goal is to improve the performance of the physical security program, leading to a cost-effective way to reduce the company’s risk. You should establish a performance baseline and then continually evaluate performance to ensure that the firm’s protection goals are being met. Examples of possible performance metrics include: number of successful attacks, number of successful attacks, and time taken for attacks.

×：Design program.  

Designing the program is wrong because it should be done after the risk analysis. Once the level of risk is understood, then the design phase can be done to protect against the threats identified in the risk analysis. The design of deterrents, delays, detections, assessments, and responses will incorporate the necessary controls for each category of the program.

×：Implement countermeasures.  

Wrong because implementing countermeasures is one of the last steps in the process of deploying a physical security program.

〇：Known Plaintext Attacks

A known-plaintext attack is a situation in which a decryptor can obtain plaintext indiscriminately. A ciphertext-alone attack is a situation where a decryptor can acquire ciphertext indiscriminately. A known-plaintext attack acquires the plaintext but does not know what ciphertext it is paired with, meaning that decryption is attempted with only two random ciphertexts. In this situation, it is difficult to decrypt. Therefore, the correct answer is “known-plaintext attack.

×：Selective Plaintext Attack

A choice-plaintext attack is a situation in which the decryptor can freely choose the plaintext to acquire and obtain the ciphertext.

×：Adaptive Choice Plaintext Attack

An adaptive choice-plaintext attack is a situation in which the decryptor can freely choose which plaintext to acquire and acquire the ciphertext, and can repeat the acquisition again after seeing the result.

×：None of the above

It is rare for the answer to be “none of the above” when the choice is “most of the above.

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：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：Statistically predictable

The two main types of symmetric algorithms are block ciphers and stream ciphers. Block ciphers perform a mathematical function on a block of bits at a time. Stream ciphers do not divide the message into blocks. Instead, a stream cipher treats the message as a stream of bits and performs the mathematical function on each bit individually. If it were statistically predictable, it would not be a practical encryption technique in the first place.

×：Statistically Fair Keystreams

Statistically fair keystreams are an element of good stream ciphers. Therefore, it is incorrect. Another way to say a statistically unbiased keystream is that it is a highly random keystream that is difficult to predict.

×：The repetitive pattern of bit strings treated in a keystream is long.

Another way to say the randomness of a keystream is that it is highly random, with long repetitions = rarely repeated = highly random.

×：The keystream is irrelevant to the key.

A keystream that is not related to a key is an element of a good stream cipher. Therefore, it is incorrect. This is important because the key provides the randomness of the encryption process.

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：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：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.

In an asymmetric algorithm, every user must have at least one key pair (private and public key). In a public key system, each entity has a separate key. The formula for determining the number of keys needed in this environment is by the number N × 2, where N is the number of people to distribute. In other words, 260 x 2 = 520. Therefore, the correct answer is 520.

〇：Brewer-Nash Model

The Chinese Wall Model is a security model that focuses on the flow of information within an organization, such as insider trading. Insider trading occurs when inside information leaks to the outside world. In reality, information can spread to unexpected places as it is passed on orally to unrelated parties. In order to take such information flow into account, access privileges are determined in a simulation-like manner. Therefore, the correct answer is the “Chinese Wall Model (Brewer-Nash Model).

×：Lattice-based Access Control

Lattice-based access control is to assume that a single entity can have multiple access rights and to consider access control as all possible relationships under a certain condition.

×：Biba Model

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

×：Harrison-Ruzzo-Ullman Model

The Harrison-Ruzzo-Ullman model is a model that aggregates the eight rules of the Graham-Denning model into six rules using an access control matrix.