harm or damage.
Criticality The level to which information is mission critical is its measure of criticality. The higher the level of criticality, the more likely the need to maintain the confidentiality of the information. High levels of criticality are essential to the operation or function of an organization.
Concealment Concealment is the act of hiding or preventing disclosure. Often concealment is viewed as a means of cover, obfuscation, or distraction.
Secrecy Secrecy is the act of keeping something a secret or preventing the disclosure of information.
Privacy Privacy refers to keeping information confidential that is personally identifiable or that might cause harm, embarrassment, or disgrace to someone if revealed.
Seclusion Seclusion involves storing something in an out-of-the-way location. This location can also provide strict access controls. Seclusion can help enforcement confidentiality protections.
Isolation Isolation is the act of keeping something separated from others. Isolation can be used to prevent commingling of information or disclosure of information.
Each organization needs to evaluate the nuances of confidentiality they wish to enforce. Tools and technology that implements one form of confidentiality might not support or allow other forms.
The second principle of the CIA Triad is integrity. For integrity to be maintained, objects must retain their veracity and be intentionally modified by only authorized subjects. If a security mechanism offers integrity, it offers a high level of assurance that the data, objects, and resources are unaltered from their original protected state. Alterations should not occur while the object is in storage, in transit, or in process. Thus, maintaining integrity means the object itself is not altered and the operating system and programming entities that manage and manipulate the object are not compromised.
Integrity can be examined from three perspectives:
■ Preventing unauthorized subjects from making modifications
■ Preventing authorized subjects from making unauthorized modifications, such as mistakes
■ Maintaining the internal and external consistency of objects so that their data is a correct and true reflection of the real world and any relationship with any child, peer, or parent object is valid, consistent, and verifiable
For integrity to be maintained on a system, controls must be in place to restrict access to data, objects, and resources. Additionally, activity logging should be employed to ensure that only authorized users are able to access their respective resources. Maintaining and validating object integrity across storage, transport, and processing requires numerous variations of controls and oversight.
Numerous attacks focus on the violation of integrity. These include viruses, logic bombs, unauthorized access, errors in coding and applications, malicious modification, intentional replacement, and system back doors.
As with confidentiality, integrity violations are not limited to intentional attacks. Human error, oversight, or ineptitude accounts for many instances of unauthorized alteration of sensitive information. Events that lead to integrity breaches include accidentally deleting files; entering invalid data; altering configurations, including errors in commands, codes, and scripts; introducing a virus; and executing malicious code such as a Trojan horse. Integrity violations can occur because of the actions of any user, including administrators. They can also occur because of an oversight in a security policy or a misconfigured security control.
Numerous countermeasures can ensure integrity against possible threats. These include strict access control, rigorous authentication procedures, intrusion detection systems, object/data encryption, hash total verifications (see Chapter 6, “Cryptography and Symmetric Key Algorithms”), interface restrictions, input/function checks, and extensive personnel training.
Integrity is dependent on confidentiality. Without confidentiality, integrity cannot be maintained. Other concepts, conditions, and aspects of integrity include accuracy, truthfulness, authenticity, validity, nonrepudiation, accountability, responsibility, completeness, and comprehensiveness.
The third principle of the CIA Triad is availability, which means authorized subjects are granted timely and uninterrupted access to objects. If a security mechanism offers availability, it offers a high level of assurance that the data, objects, and resources are accessible to authorized subjects. Availability includes efficient uninterrupted access to objects and prevention of denial-of-service (DoS) attacks. Availability also implies that the supporting infrastructure – including network services, communications, and access control mechanisms – is functional and allows authorized users to gain authorized access.
For availability to be maintained on a system, controls must be in place to ensure authorized access and an acceptable level of performance, to quickly handle interruptions, to provide for redundancy, to maintain reliable backups, and to prevent data loss or destruction.
There are numerous threats to availability. These include device failure, software errors, and environmental issues (heat, static, flooding, power loss, and so on). There are also some forms of attacks that focus on the violation of availability, including DoS attacks, object destruction, and communication interruptions.
As with confidentiality and integrity, violations of availability are not limited to intentional attacks. Many instances of unauthorized alteration of sensitive information are caused by human error, oversight, or ineptitude. Some events that lead to availability breaches include accidentally deleting files, overutilizing a hardware or software component, underallocating resources, and mislabeling or incorrectly classifying objects. Availability violations can occur because of the actions of any user, including administrators. They can also occur because of an oversight in a security policy or a misconfigured security control.
Numerous countermeasures can ensure availability against possible threats. These include designing intermediary delivery systems properly, using access controls effectively, monitoring performance and network traffic, using firewalls and routers to prevent DoS attacks, implementing redundancy for critical systems, and maintaining and testing backup systems. Most security policies, as well as business continuity planning (BCP), focus on the use of fault tolerance features at the various levels of access/storage/security (that is, disk, server, or site) with the goal of eliminating single points of failure to maintain availability of critical systems.
Availability depends on both integrity and confidentiality. Without integrity and confidentiality, availability cannot be maintained. Other concepts, conditions, and aspects of availability include usability, accessibility, and timeliness.
CIA Priority
Every organization has unique security requirements. On the CISSP exam, most security concepts are discussed in general terms, but in the real world, general concepts and best practices don’t get the job done. The management team and security team must work together to prioritize an organization’s security needs. This includes establishing a budget and spending plan, allocating expertise and hours, and focusing the IT and security staff efforts. One key aspect of this effort is to prioritize the security requirements of the organization. Knowing which tenet or asset is more important than another guides the creation of a security stance and ultimately the deployment of a security solution. Often, getting started in establishing priorities is a challenge. A possible solution to this challenge is to start with prioritizing the three primary security tenets of confidentiality, integrity, and availability. Defining which of these elements is most important to the
