The combination that would most negatively affect availability is denial of service (DoS) attacks and outdated hardware. Availability is the property or the condition of a system or a network to be accessible and usable by the authorized users or customers, whenever and wherever they need it. Availability can be measured by various metrics, such as uptime, downtime, response time, or reliability. Availability can be affected by various factors, such as hardware, software, network, human, or environmental factors. Denial of service (DoS) attacks and outdated hardware are two factors that can negatively affect availability, as they can cause or contribute to the following consequences:

Denial of service (DoS) attacks are malicious attacks that aim to disrupt or degrade the availability of a system or a network, by overwhelming or exhausting its resources, such as bandwidth, memory, or processing power, with a large number or a high frequency of requests or packets. Denial of service (DoS) attacks can prevent or delay the legitimate users or customers from accessing or using the system or the network, and they can cause errors, failures, or crashes to the system or the network.

Outdated hardware are hardware components that are old, obsolete, or unsupported, and that do not meet the current or the expected requirements or standards of the system or the network, such as performance, functionality, or security. Outdated hardware can reduce or limit the availability of the system or the network, as they can cause malfunctions, breakdowns, or incompatibilities to the system or the network, and they can be difficult or costly to maintain, repair, or replace.

The combination of denial of service (DoS) attacks and outdated hardware would most negatively affect availability, as they can have a synergistic or a cumulative effect on the system or the network, and they can exacerbate or amplify each other’s impact. For example, denial of service (DoS) attacks can exploit or target the vulnerabilities or the weaknesses of the outdated hardware, and they can cause more damage or disruption to the system or the network. Outdated hardware can increase or prolong the susceptibility or the recovery of the system or the network to the denial of service (DoS) attacks, and they can reduce or hinder the resilience or the mitigation of the system or the network to the denial of service (DoS) attacks. Unauthorized transactions and outdated hardware, fire and accidental changes to data, and unauthorized transactions and denial of service attacks are not the combinations that would most negatively affect availability, although they may be related or possible combinations. Unauthorized transactions and outdated hardware are two factors that can negatively affect the confidentiality and the integrity of the data, rather than the availability of the system or the network, as they can cause or contribute to the following consequences:

Unauthorized transactions are malicious or improper activities that involve accessing, modifying, or transferring the data on a system or a network, without the permission or the consent of the owner or the custodian of the data, such as theft, fraud, or sabotage. Unauthorized transactions can compromise or damage the confidentiality and the integrity of the data, as they can expose or disclose the data to unauthorized parties, or they can alter or destroy the data.

Outdated hardware are hardware components that are old, obsolete, or unsupported, and that do not meet the current or the expected requirements or standards of the system or the network, such as performance, functionality, or security. Outdated hardware can compromise or damage the confidentiality and the integrity of the data, as they can be vulnerable or susceptible to attacks or errors, or they can be incompatible or inconsistent with the data.

Fire and accidental changes to data are two factors that can negatively affect the availability and the integrity of the data, rather than the availability of the system or the network, as they can cause or contribute to the following consequences:

Fire is a physical or an environmental hazard that involves the combustion or the burning of a material or a substance, such as wood, paper, or plastic, and that produces heat, light, or smoke. Fire can damage or destroy the availability and the integrity of the data, as it can consume or melt the physical media or devices that store the data, such as hard disks, tapes, or CDs, or it can corrupt or erase the data on the media or devices.

Accidental changes to data are human or operational errors that involve modifying or altering the data on a system or a network, without the intention or the awareness of the user or the operator, such as typos, misconfigurations, or overwrites. Accidental changes to data can damage or destroy the availability and the integrity of the data, as they can make the data inaccessible or unusable, or they can make the data inaccurate or unreliable.

Unauthorized transactions and denial of service attacks are two factors that can negatively affect the confidentiality and the availability of the system or the network, rather than the availability of the system or the network, as they can cause or contribute to the following consequences:

Unauthorized transactions are malicious or improper activities that involve accessing, modifying, or transferring the data on a system or a network, without the permission or the consent of the owner or the custodian of the data, such as theft, fraud, or sabotage. Unauthorized transactions can compromise or damage the confidentiality and the availability of the system or the network, as they can expose or disclose the data to unauthorized parties, or they can consume or divert the resources of the system or the network.

Denial of service (DoS) attacks are malicious attacks that aim to disrupt or degrade the availability of a system or a network, by overwhelming or exhausting its resources, such as bandwidth, memory, or processing power, with a large number or a high frequency of requests or packets. Denial of service (DoS) attacks can compromise or damage the confidentiality and the availability of the system or the network, as they can prevent or delay the legitimate users or customers from accessing or using the system or the network, and they can cause errors, failures, or crashes to the system or the network.

There are different terms related to Security Engineering, which is the discipline of designing, building, and maintaining secure systems. According to [1], Security Engineering is the art and science of building dependable systems. Some common terms and their definitions are:

Risk : A measure of the extent to which an entity is threatened by a potential circumstance or event, the adverse impacts that would arise if the circumstance or event occurs, and the likelihood of occurrence. Risk is also defined as the combination of the probability of an event and its consequence. Risk can be assessed, analyzed, and managed using various methods and techniques, such as risk identification, risk evaluation, risk treatment, and risk monitoring.

Security Risk Treatment : The method used to identify the confidentiality, integrity, and availability requirements for organizational and system assets and to characterize the adverse impact or consequences should the asset be lost, modified, degraded, disrupted, compromised, or become unavailable. Security risk treatment is also known as security risk analysis, security risk assessment, or security impact analysis, and it is part of the security certification and accreditation (C & A) process. Security risk treatment can help to determine the security categorization, security controls, and security assurance level for the assets and the system.

Protection Needs Assessment : The method used to identify and characterize the dangers anticipated throughout the life cycle of the system. Protection needs assessment is also known as threat assessment, threat analysis, or threat modeling, and it is part of the security engineering process. Protection needs assessment can help to identify the potential sources, methods, and objectives of the attackers, as well as the vulnerabilities and weaknesses of the system. Protection needs assessment can also help to prioritize the protection needs and countermeasures for the system.

Threat Assessment : The method used to identify feasible security risk mitigation options and plans. Threat assessment is also known as risk mitigation, risk response, or risk treatment, and it is part of the risk management process. Threat assessment can help to select and implement the appropriate security controls and strategies to reduce the risk to an acceptable level, or to transfer, avoid, or accept the risk. Threat assessment can also help to monitor and evaluate the effectiveness and performance of the security controls and strategies.

The following table shows the possible matching of the Security Engineering terms to their definitions:

 Security Engineering terms and definitions are important to understand and apply in the context of developing, deploying, and maintaining secure systems. Security Engineering terms and definitions can help to establish a common language and framework for security professionals, stakeholders, and users, and to communicate the security objectives, requirements, and issues of the system. Security Engineering terms and definitions can also help to guide the security engineering process, which involves the following steps: security planning, security analysis, security design, security implementation, security testing, security deployment, security operation, and security maintenance. Security Engineering terms and definitions can also help to support the security certification and accreditation (C & A) process, which involves the following tasks: security categorization, security control selection, security control implementation, security control assessment, security certification, security accreditation, and security monitoring. 

A digital watermark is a hidden signal embedded in a data file that can be used to identify the owner, source, or authenticity of the data. A watermark is difficult to detect and remove without degrading the quality of the data. However, one way that a watermark might still be inadvertently removed is by truncating parts of the data, such as cropping an image or cutting a video. This might affect the location or size of the watermark and make it unreadable or invalid.  References :  Official (ISC)2 CISSP CBK Reference, Fifth Edition , page 507;  CISSP For Dummies, 7th Edition , page 344.

A common characteristic of privacy is notice to the subject of the existence of a database containing relevant credit card data. Privacy is the right or the expectation of an individual or a group to control or limit the collection, use, disclosure, or retention of their personal or sensitive information by others. Privacy can involve various principles or tenets that are shared across different regulatory standards or frameworks, such as GDPR, HIPAA, or PIPEDA. One of the common privacy principles or tenets is notice, which requires that the data subject or the individual whose information is collected or processed should be informed or notified of the following aspects:

The existence of a database or a system that contains their information, such as credit card data, health records, or biometric data.

The purpose or the reason for collecting or processing their information, such as billing, marketing, or research.

The identity or the contact details of the data controller or the party who is responsible for collecting or processing their information, such as a company, an organization, or a government agency.

The rights or the choices of the data subject regarding their information, such as the right to access, correct, delete, or withdraw their information.

Notice can provide some benefits for privacy, such as enhancing the transparency and the accountability of the data collection or processing activities, respecting the consent and the preferences of the data subject, and supporting the compliance and the enforcement of the privacy laws or regulations. Provision for maintaining an audit trail of access to the private data, process for the subject to inspect and correct personal data on-site, and database requirements for integration of privacy data are not common characteristics of privacy, although they may be related or important aspects of privacy. Provision for maintaining an audit trail of access to the private data is a technique that involves recording and storing the logs or the records of the events or the activities that occur on a database or a system that contains private data, such as who accessed, modified, or deleted the data, when, where, how, and why. Provision for maintaining an audit trail of access to the private data can provide some benefits for privacy, such as enhancing the visibility and the traceability of the data access or processing activities, preventing or detecting any unauthorized or improper access or processing, and supporting the audit and the compliance activities. However, provision for maintaining an audit trail of access to the private data is not a common characteristic of privacy, as it is not a principle or a tenet that is shared across different regulatory standards or frameworks, and it may vary depending on the type or the nature of the private data. Process for the subject to inspect and correct personal data on-site is a technique that involves providing a mechanism or a procedure for the data subject to access and verify their personal data that is stored or processed on a database or a system, and to request or make any changes or corrections if needed, such as updating their name, address, or email. Process for the subject to inspect and correct personal data on-site can provide some benefits for privacy, such as enhancing the accuracy and the reliability of the personal data, respecting the rights and the interests of the data subject, and supporting the compliance and the enforcement of the privacy laws or regulations. However, process for the subject to inspect and correct personal data on-site is not a common characteristic of privacy, as it is not a principle or a tenet that is shared across different regulatory standards or frameworks, and it may vary depending on the type or the nature of the personal data. Database requirements for integration of privacy data are the specifications or the criteria that a database or a system that contains or processes privacy data should meet or comply with, such as the design, the architecture, the functionality, or the security of the database or the system. Database requirements for integration of privacy data can provide some benefits for privacy, such as enhancing the performance and the functionality of the database or the system, preventing or mitigating some types of attacks or vulnerabilities, and supporting the audit and the compliance activities. However, database requirements for integration of privacy data are not a common characteristic of privacy, as they are not a principle or a tenet that is shared across different regulatory standards or frameworks, and they may vary depending on the type or the nature of the privacy data. 

Fuzzing is a technique that is known to be effective in spotting resource exhaustion problems, especially with resources such as processes, memory, and connections. Fuzzing is a type of testing that involves sending random, malformed, or unexpected input to the system or application, and observing its behavior and response. Fuzzing can help to identify resource exhaustion problems, such as memory leaks, buffer overflows, or connection timeouts, which can affect the availability, functionality, or security of the system or application. Fuzzing can also help to discover other types of vulnerabilities, such as logic errors, input validation errors, or exception handling errors. Automated dynamic analysis, automated static analysis, and manual code review are not techniques that are known to be effective in spotting resource exhaustion problems, although they may be used for other types of testing or analysis.  References :  CISSP All-in-One Exam Guide, Eighth Edition , Chapter 8: Software Development Security, page 1001;  Official (ISC)2 Guide to the CISSP CBK, Fifth Edition , Chapter 7: Software Development Security, page 923.

 When implementing a data classification program, it is important to avoid too much granularity, because the process will require too many resources. Data classification is the process of assigning a level of sensitivity or criticality to data based on its value, impact, and legal requirements. Data classification helps to determine the appropriate security controls and handling procedures for the data. However, data classification is not a simple or straightforward process, as it involves many factors, such as the nature, context, and scope of the data, the stakeholders, the regulations, and the standards. If the data classification program has too many levels or categories of data, it will increase the complexity, cost, and time of the process, and reduce the efficiency and effectiveness of the data protection. Therefore, data classification should be done with a balance between granularity and simplicity, and follow the principle of proportionality, which means that the level of protection should be proportional to the level of risk.

The other options are not the main reasons to avoid too much granularity in data classification, but rather the potential challenges or benefits of data classification. It will be difficult to apply to both hardware and software is a challenge of data classification, as it requires consistent and compatible methods and tools for labeling and protecting data across different types of media and devices. It will be difficult to assign ownership to the data is a challenge of data classification, as it requires clear and accountable roles and responsibilities for the creation, collection, processing, and disposal of data. The process will be perceived as having value is a benefit of data classification, as it demonstrates the commitment and awareness of the organization to protect its data assets and comply with its obligations.

Asymmetric Card Authentication Key (CAK) challenge-response is an effective control in preventing electronic cloning of RFID based access cards. RFID based access cards are contactless cards that use radio frequency identification (RFID) technology to communicate with a reader and grant access to a physical or logical resource. RFID based access cards are vulnerable to electronic cloning, which is the process of copying the data and identity of a legitimate card to a counterfeit card, and using it to impersonate the original cardholder and gain unauthorized access. Asymmetric CAK challenge-response is a cryptographic technique that prevents electronic cloning by using public key cryptography and digital signatures to verify the authenticity and integrity of the card and the reader. Asymmetric CAK challenge-response works as follows:

The card and the reader each have a pair of public and private keys, and the public keys are exchanged and stored in advance.

When the card is presented to the reader, the reader generates a random number (nonce) and sends it to the card.

The card signs the nonce with its private key and sends the signature back to the reader.

The reader verifies the signature with the card’s public key and grants access if the verification is successful.

The card also verifies the reader’s identity by requesting its signature on the nonce and checking it with the reader’s public key.

Asymmetric CAK challenge-response prevents electronic cloning because the private keys of the card and the reader are never transmitted or exposed, and the signatures are unique and non-reusable for each transaction. Therefore, a cloned card cannot produce a valid signature without knowing the private key of the original card, and a rogue reader cannot impersonate a legitimate reader without knowing its private key.

The other options are not as effective as asymmetric CAK challenge-response in preventing electronic cloning of RFID based access cards. Personal Identity Verification (PIV) is a standard for federal employees and contractors to use smart cards for physical and logical access, but it does not specify the cryptographic technique for RFID based access cards. Cardholder Unique Identifier (CHUID) authentication is a technique that uses a unique number and a digital certificate to identify the card and the cardholder, but it does not prevent replay attacks or verify the reader’s identity. Physical Access Control System (PACS) repeated attempt detection is a technique that monitors and alerts on multiple failed or suspicious attempts to access a resource, but it does not prevent the cloning of the card or the impersonation of the reader.

The best description of the responsibilities of a data owner is determining the impact the information has on the mission of the organization. A data owner is a person or entity that has the authority and accountability for the creation, collection, processing, and disposal of a set of data. A data owner is also responsible for defining the purpose, value, and classification of the data, as well as the security requirements and controls for the data. A data owner should be able to determine the impact the information has on the mission of the organization, which means assessing the potential consequences of losing, compromising, or disclosing the data. The impact of the information on the mission of the organization is one of the main criteria for data classification, which helps to establish the appropriate level of protection and handling for the data.

The other options are not the best descriptions of the responsibilities of a data owner, but rather the responsibilities of other roles or functions related to data management. Ensuring quality and validation through periodic audits for ongoing data integrity is a responsibility of a data steward, who is a person or entity that oversees the quality, consistency, and usability of the data. Maintaining fundamental data availability, including data storage and archiving is a responsibility of a data custodian, who is a person or entity that implements and maintains the technical and physical security of the data. Ensuring accessibility to appropriate users, maintaining appropriate levels of data security is a responsibility of a data controller, who is a person or entity that determines the purposes and means of processing the data.

Identity as a Service (IDaaS) is the best contract in offloading the task of account management from the IT staff. IDaaS is a cloud-based service that provides identity and access management (IAM) functions, such as user authentication, authorization, provisioning, deprovisioning, password management, single sign-on (SSO), and multifactor authentication (MFA). IDaaS can help the organization to streamline and automate the account management process, reduce the workload and costs of the IT staff, and improve the security and compliance of the user accounts. IDaaS can also support the contractors who have limited onsite time, as they can access the organization’s resources remotely and securely through the IDaaS provider.

The other options are not as effective as IDaaS in offloading the task of account management from the IT staff, as they do not provide IAM functions. Platform as a Service (PaaS) is a cloud-based service that provides a platform for developing, testing, and deploying applications, but it does not manage the user accounts for the applications. Desktop as a Service (DaaS) is a cloud-based service that provides virtual desktops for users to access applications and data, but it does not manage the user accounts for the virtual desktops. Software as a Service (SaaS) is a cloud-based service that provides software applications for users to use, but it does not manage the user accounts for the software applications.

In a data classification scheme, the data is owned by the business managers. Business managers are the persons or entities that have the authority and accountability for the creation, collection, processing, and disposal of a set of data. Business managers are also responsible for defining the purpose, value, and classification of the data, as well as the security requirements and controls for the data. Business managers should be able to determine the impact the information has on the mission of the organization, which means assessing the potential consequences of losing, compromising, or disclosing the data. The impact of the information on the mission of the organization is one of the main criteria for data classification, which helps to establish the appropriate level of protection and handling for the data.

The other options are not the data owners in a data classification scheme, but rather the other roles or functions related to data management. System security managers are the persons or entities that oversee the security of the information systems and networks that store, process, and transmit the data. They are responsible for implementing and maintaining the technical and physical security of the data, as well as monitoring and auditing the security performance and incidents. Information Technology (IT) managers are the persons or entities that manage the IT resources and services that support the business processes and functions that use the data. They are responsible for ensuring the availability, reliability, and scalability of the IT infrastructure and applications, as well as providing technical support and guidance to the users and stakeholders. End users are the persons or entities that access and use the data for their legitimate purposes and needs. They are responsible for complying with the security policies and procedures for the data, as well as reporting any security issues or violations.

 When developing an information security management system (ISMS), an initial consideration is to understand the value of the information assets that the organization owns or processes. An information asset is any data, information, or knowledge that has value to the organization and supports its mission, objectives, and operations. Understanding the value of the information assets helps to determine the appropriate level of protection and investment for them, as well as the potential impact and consequences of losing, compromising, or disclosing them. Understanding the value of the information assets also helps to identify the stakeholders, owners, and custodians of the information assets, and their roles and responsibilities in the ISMS.

The other options are not initial considerations, but rather subsequent or concurrent considerations when developing an ISMS. Identifying the contractual security obligations that apply to the organizations is a consideration that depends on the nature, scope, and context of the information assets, as well as the relationships and agreements with the external parties. Identifying the level of residual risk that is tolerable to management is a consideration that depends on the risk appetite and tolerance of the organization, as well as the risk assessment and analysis of the information assets. Identifying relevant legislative and regulatory compliance requirements is a consideration that depends on the legal and ethical obligations and expectations of the organization, as well as the jurisdiction and industry of the information assets.

The passage of time is one of the factors that affects the classification of data. Data classification is the process of assigning a level of sensitivity or criticality to data based on its value, impact, and legal requirements. Data classification helps to determine the appropriate security controls and handling procedures for the data. However, data classification is not static, but dynamic, meaning that it can change over time depending on various factors. One of these factors is the passage of time, which can affect the relevance, usefulness, or sensitivity of the data. For example, data that is classified as confidential or secret at one point in time may become obsolete, outdated, or declassified at a later point in time, and thus require a lower level of protection. Conversely, data that is classified as public or unclassified at one point in time may become more valuable, sensitive, or regulated at a later point in time, and thus require a higher level of protection. Therefore, data classification should be reviewed and updated periodically to reflect the changes in the data over time.

The other options are not factors that affect the classification of data, but rather the outcomes or components of data classification. Assigned security label is the result of data classification, which indicates the level of sensitivity or criticality of the data. Multilevel Security (MLS) architecture is a system that supports data classification, which allows different levels of access to data based on the clearance and need-to-know of the users. Minimum query size is a parameter that can be used to enforce data classification, which limits the amount of data that can be retrieved or displayed at a time.

 When assigning ownership of an asset to a department, the most important factor is to ensure individual accountability for the asset. Individual accountability means that each person who has access to or uses the asset is responsible for its protection and proper handling. Individual accountability also implies that each person who causes or contributes to a security breach or incident involving the asset can be identified and held liable. Individual accountability can be achieved by implementing security controls such as authentication, authorization, auditing, and logging.

The other options are not as important as ensuring individual accountability, as they do not directly address the security risks associated with the asset. The department should report to the business owner is a management issue, not a security issue. Ownership of the asset should be periodically reviewed is a good practice, but it does not prevent misuse or abuse of the asset. All members should be trained on their responsibilities is a preventive measure, but it does not guarantee compliance or enforcement of the responsibilities.

 Software security functional requirements must be defined after the business functional analysis and the data security categorization have been performed in the Software Development Life Cycle (SDLC). The SDLC is a process that involves planning, designing, developing, testing, deploying, operating, and maintaining a system, using various models and methodologies, such as waterfall, spiral, agile, or DevSecOps. The SDLC can be divided into several phases, each with its own objectives and activities, such as:

System initiation: This phase involves defining the scope, purpose, and objectives of the system, identifying the stakeholders and their needs and expectations, and establishing the project plan and budget.

System acquisition and development: This phase involves designing the architecture and components of the system, selecting and procuring the hardware and software resources, developing and coding the system functionality and features, and integrating and testing the system modules and interfaces.

System implementation: This phase involves deploying and installing the system to the production environment, migrating and converting the data and applications from the legacy system, training and educating the users and staff on the system operation and maintenance, and evaluating and validating the system performance and effectiveness.

System operations and maintenance: This phase involves operating and monitoring the system functionality and availability, maintaining and updating the system hardware and software, resolving and troubleshooting any issues or problems, and enhancing and optimizing the system features and capabilities.

Software security functional requirements are the specific and measurable security features and capabilities that the system must provide to meet the security objectives and requirements. Software security functional requirements are derived from the business functional analysis and the data security categorization, which are two tasks that are performed in the system initiation phase of the SDLC. The business functional analysis is the process of identifying and documenting the business functions and processes that the system must support and enable, such as the inputs, outputs, workflows, and tasks. The data security categorization is the process of determining the security level and impact of the system and its data, based on the confidentiality, integrity, and availability criteria, and applying the appropriate security controls and measures. Software security functional requirements must be defined after the business functional analysis and the data security categorization have been performed, because they can ensure that the system design and development are consistent and compliant with the security objectives and requirements, and that the system security is aligned and integrated with the business functions and processes.

The other options are not the phases of the SDLC when the software security functional requirements must be defined, but rather phases that involve other tasks or activities related to the system design and development. After the system preliminary design has been developed and the data security categorization has been performed is not the phase when the software security functional re quirements must be defined, but rather the phase when the system architecture and components are designed, based on the system scope and objectives, and the data security categorization is verified and validated. After the vulnerability analysis has been performed and before the system detailed design begins is not the phase when the software security functional requirements must be defined, but rather the phase when the system design and components are evaluated and tested for the security effectiveness and compliance, and the system detailed design is developed, based on the system architecture and components. After the system preliminary design has been developed and before the data security categorization begins is not the phase when the software security functional requirements must be defined, but rather the phase when the system architecture and components are designed, based on the system scope and objectives, and the data security categorization is initiated and planned.

 A threat related to the use of web-based client side input validation is that users would be able to alter the input after validation has occurred. Client side input validation is performed on the user’s browser using JavaScript or other scripting languages. It can provide a faster and more user-friendly feedback to the user, but it can also be easily bypassed or manipulated by an attacker who disables JavaScript, uses a web proxy, or modifies the source code of the web page. Therefore, client side input validation should not be relied upon as the sole or primary method of preventing malicious or malformed input from reaching the web server.  Server side input validation is also necessary to ensure the security and integrity of the web application 5 6 .  References :  5 : Input Validation - OWASP Cheat Sheet Series 7 6 : Input Validation vulnerabilities and how to fix them