Remediation plan
A plan to perform the remediation of one or more threats or vulnerabilities facing an organization’s systems. The plan typically includes options to remove threats and vulnerabilities and priorities for performing the remediation.
Remote access
(1) Access to an organizational information system by a user or an information system communicating through an external, non-organization-controlled network (e.g., the Internet). (2) The ability for an organization’s users to access its non-public computing resources from locations other than the organization’s facilities.
Remote administration tool
A program installed on a system that allows remote attackers to gain access to the system as needed.
Remote journaling
Transaction logs or journals are transmitted to a remote location. If the server needed to be recovered, the logs or journals could be used to recover transactions, applications, or database changes that occurred after the last server backup. Remote journaling can either be conducted though batches or be communicated continuously using buffering software. Remote journaling and electronic vaulting require a dedicated offsite location (that is, hot-site or offsite storage site) to receive the transmissions and a connection with limited bandwidth.
Remote maintenance
Maintenance activities conducted by individuals communicating through an external, nonorganization-controlled network (e.g., the Internet).
Remote maintenance attack
Some hardware and software vendors who have access to an organization’s computer systems for problem diagnosis and remote maintenance work can modify database contents or reconfigure network elements to their advantage.
Remote system control
Remotely using a computer at an organization from a telework computer.
Removable media
Portable electronic storage media such as magnetic, optical, and solid-state devices, which can be inserted into and removed from a computing device, and are used to store text, video, audio, and image information. Such devices have no independent processing capabilities. Examples of removable media include hard disks, zip drives, compact disks, thumb drives, flash drives, pen drives, and similar universal serial bus (USB) storage devices. Removable media are less risky than the nonremovable media in terms of security breaches.
Repeater
A device to amplify the received signals and it operates in the physical layer of the ISO/OSI reference model.
Replay
One can eavesdrop upon another’s authentication exchange and learn enough to impersonate a user. It is used in conducting an impersonation attack.
Replay attack
(1) An attack that involves the capture of transmitted authentication or access control information and its subsequent retransmission with the intent of producing an unauthorized effect or gaining unauthorized access. (2) An attack in which the attacker can replay previously captured messages (between a legitimate claimant and a verifier) to masquerade as that claimant to the verifier or vice versa.
Repository
A database containing information and data relating to certificates; may also be referred to as a directory.
Request for comment (RFC)
An Internet standard, developed, and published by the Internet Engineering Task Force (IETF).
Requirement
A statement of the system behavior needed to enforce a given policy. Requirements are used to derive the technical specification of a system.
Reserve keying material
Cryptographic key held to satisfy unplanned needs. It is also called a contingency key where a key is held for use under specific operational conditions or in support of specific contingency plans.
Residue
Data left in storage after information-processing operations are complete; but before degaussing or overwriting has taken place.
Residual data
Data from deleted files or earlier versions of existing files.
Residual risk
The remaining, potential risk after all IT security measures are applied. There is a residual risk associated with each threat.
Resilience
(1) The capability to quickly adapt and recover from any known or unknown changes to the environment through holistic implementation of risk management, contingency measures, and continuity planning. (2) The capability of a computer system to continue to function correctly despite the existence of a fault or faults in one or more of its component parts.
Resource
Anything used or consumed while performing a function. The categories of resources are time, information, objects (information containers), or processors (the ability to use information). Specific examples are CPU time, terminal connect time, amount of directly addressable memory, disk space, number of input/output requests per minute, and so on.
Resource encapsulation
A method by which the reference-monitor mediates accesses to an information system resource. Resource is protected and not directly accessible by a subject. Satisfies requirement for accurate auditing of resource usage.
Resource isolation
It is the containment of subjects and objects in a system in such a way that they are separated from one another, as well as from the protection controls of the operating system.
Responder
The entity that responds to the initiator of the authentication exchange.
Restart
The resumption of the execution of a computer program using the data recorded at a checkpoint. This is a technical and recovery control.
Restore
The process of retrieving a data set migrated to off-line storage and restoring it to online storage. This is a technical and recovery control.
Retention program
A program to save documents, forms, history logs, master and transaction data files, computer programs (both source and object level), and other documents of the system until no longer needed. Retention periods should satisfy organization and legal requirements.
Return on investment (ROI)
A ratio indicating what percentage of the investment the annual benefit in terms of cash flow is. It is calculated as annual operating cash inflows divided by the annual net investment.
The ROI can be used to assess the financial feasibility of an investment in information security program.
Reverse engineering
Used to gain a better understanding of the current system’s complexity and functionality and to identify “trouble spots.” Errors can be detected and corrected, and modifications can be made to improve system performance. The information gained during reverse engineering can be used to restructure the system, thus making the system more maintainable. Maintenance requests can then be accomplished easily and quickly. Software reengineering also enables the reuse of software components from existing systems. The knowledge gained from reverse engineering can be used to identify candidate systems composed of reusable components, which can then be used in other applications. Reverse engineering can also be used to identify functionally redundant parts in existing application systems.
Reversible data hiding
A technique that allows images to be authenticated and then restored to their original form by removing the watermark and replacing the image data, which had been overwritten. This makes the images acceptable for legal purposes.