〇：Run an algorithm that identifies unused committed memory and informs the operating system that memory is available.

This answer describes the function of the garbage collector, not the memory manager. The garbage collector is a countermeasure against memory leaks. It is software that runs an algorithm to identify unused committed memory and tells the operating system to mark that memory as “available. Different types of garbage collectors work with different operating systems, programming languages, and algorithms.

In some cases, a four-choice question can be answered without knowing the exact answer; since there is only one correct answer in a four-choice question, the answers can be grouped together to reduce it to “since they are saying the same thing, it is not right that only one of them is correct, therefore they are both wrong.

There are two answers to the effect of controlling the process to handle memory appropriately, but if the memory manager does not have that functionality, both would be correct, and therefore can be eliminated from the choices in the first place.

×：If processes need to use the same shared memory segment, use complex controls to guarantee integrity and confidentiality.

If processes need to use the same shared memory segment, the memory manager uses complex controls to ensure integrity and confidentiality. This is important to protect memory and the data in it, since two or more processes can share access to the same segment with potentially different access rights. The memory manager also allows many users with different levels of access rights to interact with the same application running on a single memory segment.

×：Restrict processes to interact only with the memory segments allocated to them.

The memory manager is responsible for limiting the interaction of processes to only those memory segments allocated to them. This responsibility falls under the protection category and helps prevent processes from accessing segments to which they are not allowed. Another protection responsibility of the memory manager is to provide access control to memory segments.

×：Swap contents from RAM to hard drive as needed.

This is incorrect because swapping contents from RAM to hard drive as needed is the role of memory managers in the relocation category. When RAM and secondary storage are combined, they become virtual memory. The system uses the hard drive space to extend the RAM memory space. Another relocation responsibility is to provide pointers for applications when instructions and memory segments are moved to another location in main memory.

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.

A collision is when the hash value of two different data from one hash function is the same. Hashing is one-way cryptography, which means that the original plaintext is no longer known to be one or the other.

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：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：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：Encryption and decryption are more efficient.

Elliptic curves are rich mathematical structures that have shown usefulness in many different types of applications. Elliptic curve cryptography (ECC) differs from other asymmetric algorithms because of its efficiency; ECC is efficient because it is computationally less expensive than other asymmetric algorithms. In most cases, the longer the key, the more bloated the computation to secure it, but ECC can provide the same level of protection with a shorter key size than RSA requires.

×：Provides digital signatures, secure key distribution, and encryption.

ECC is wrong because it is not the only asymmetric algorithm that provides digital signatures, secure key distribution, and encryption provided by other asymmetric algorithms such as RSA.

×：Calculated in finite discrete logarithms.

Wrong because Diffie-Hellman and El-Gamal compute with finite discrete logarithms.

×：Uses a large percentage of resources to perform the encryption.

Incorrect because ECC when compared to other asymmetric algorithms uses much less resources. Some devices, such as wireless devices and cell phones, have limited processing power, storage, power, and bandwidth. Resource utilization efficiency is very important for the encryption methods used in this type.

〇：Increased Processing Power

The increased processing power of personal computers and servers has increased the probability of successful brute force and cracking attacks against security mechanisms that were not feasible a few years ago. Today’s processors can execute an incredible number of instructions per second. These instructions can be used to break passwords, encryption keys, or direct malicious packets to be sent to the victim’s system.

×：Increased circuitry, cache memory, and multiprogramming

This is incorrect because an increase does not make a particular type of attack more powerful. Multiprogramming means loading multiple programs or processes into memory at the same time. It allows antivirus software, word processors, firewalls, and e-mail clients to run simultaneously. Cache memory is a type of memory used for fast write and read operations. If the system expects that the program logic will need to access certain information many times during processing, the information is stored in cache memory for easy and quick access.

×：Dual-mode computation

The answer is not specific and does not measure conformance to the problem. When examining microprocessor advances, there is no actual dual-mode calculation.

×：Direct Memory Access I/O

Incorrect because this method transfers instructions and data between I/O (input/output) devices and the system’s memory without using the CPU. Direct Memory Access I/O significantly increases data transfer speed.

〇：The cloud provider is provided a platform as a service that provides a computing platform that may include an operating system, database, and web servers.

Cloud computing is a term used to describe the aggregation of network and server technologies, each virtualized, to provide customers with a specific computing environment that matches their needs. This centralized control provides end users with self-service, broad access across multiple devices, resource pooling, rapid elasticity, and service monitoring capabilities.

There are different types of cloud computing products: IaaS provides virtualized servers in the cloud; PaaS allows applications to be developed individually; SaaS allows service providers to deploy services with no development required and with a choice of functionality; and IaaS allows customers to choose the type of service they want to use. ” The term “PaaS” must fit the definition of “PaaS” because it requires that “the original application configuration remains the same”. Thus, the correct answer is, “The cloud provider provides a computing platform that may include an operating system, database, and web server, where the platform as a service is provided.” The following is the correct answer

×：The cloud provider is provided with an infrastructure as a service that provides a computing platform that can include an operating system, database, and web servers.

IaaS Description.

×：The cloud provider is provided with software services that provide an infrastructure environment similar to that of a traditional data center.

This is a description of the operational benefits of cloud computing. It is not a definition.

×：The cloud provider provides software as a service in a computing platform environment where application functionality is internalized.

SaaS Description.

〇：Crime Prevention by Environmental Design (CPTED)

Crime Prevention by Environmental Design (CPTED) is a method by which crime can be reduced through proper design of the physical environment. It provides guidance on appropriate facility construction and environmental elements and crime prevention. It is used to guide the physical environment to behavioral effects that reduce crime.

×：Multi-layered defense model  

The multi-layered defense model is incorrect because it is a hierarchical architecture of physical, logical, and administrative security controls. The concept is that if one layer fails, the asset is protected by other layers. Layers should be moved from the perimeter toward the asset and implemented.

×：Hiding by Ambiguity

Concealment by ambiguity is a technique of concealment secured by concealment of information and is incorrect. Basically, it is better not to consider something to be a true secret if it is logically reachable, even if it is not public.

×：Access Control

Access control is incorrect because it is guidance by the placement of doors, fences, lighting, and landscaping as people enter. It is an abstract concept and would not fit into a concrete definition that combines sociology.

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：Well-Formed Transaction

In the Clark-Wilson model, subjects cannot access objects without going through some type of application or program that controls how this access is done. The subject (usually the user) can access the required object based on access rules within the application software, defined as “Well-Formed Transaction,” in conjunction with the application.

×：Childwall model

This is incorrect because it is another name for the Brewer Nash model created to provide access control that can be dynamically modified according to the user’s previous behavior. It is shaped by access attempts and conflicts of interest and does not allow information to flow between subjects and objects. In this model, a subject can only write to an object if the subject cannot read another object in a different data set.

×：Access tuples

The Clark-Wilson model is incorrect because it uses access triples instead of access tuples. The access triple is the subject program object. This ensures that the subject can only access the object through the authorized program.

×：Write Up and Write Down

The Clark-Wilson model is incorrect because there is no Write Up and Write Down. These rules relate to the Bell-LaPadula and Biba models. The Bell-LaPadula model contains a simple security rule that has not been read and a star property rule that has not been written down. The Biba model contains an unread simple completeness axiom and an unwritten star completeness axiom.

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：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：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：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：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.

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：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：Multiple processes are using the same resources.

The system uses hard drive space (called swap space) that is reserved to expand RAM memory space. When the system fills up volatile memory space, data is written from memory to the hard drive. When a program requests access to this data, it is returned from the hard drive to memory in specific units called page frames. Accessing data stored on hard drive pages takes longer than accessing data stored in memory because it requires read/write access to the physical disk. A security issue with using virtual swap space is that two or more processes can use the same resources and corrupt or damage data.

×：Allowing cookies to remain persistent in memory

This is incorrect because virtual storage is not associated with cookies. Virtual storage uses hard drive space to extend RAM memory space. Cookies are small text files used primarily by web browsers. Cookies can contain credentials for web sites, site preferences, and shopping history. Cookies are also commonly used to maintain web server-based sessions.

×：Side-channel attacks are possible.

Side-channel attacks are incorrect because they are physical attacks. This type of attack gathers information about how a mechanism (e.g., smart card or encryption processor) works from abandoned radiation, time spent processing, power consumed to perform a task, etc. Using the information, reverse engineer the mechanism to reveal how it performs its security task. This is not related to virtual storage.

×：Two processes can perform a denial of service attack.

The biggest threat within a system where resources are shared between processes is that one process can adversely affect the resources of another process, since the operating system requires memory to be shared among all resources. This is especially true in the case of memory. It is possible for two processes to work together to perform a denial of service attack, but this is only one of the attacks that can be performed with or without the use of virtual storage.