Adaptation and Evolution Services

Survivable system functions provided to continually improve the system’s capability to deliver essential services, typically by improving resistance, recognition, and recovery capabilities

Essential Services

Services to users of a system that must be provided even in the presence of intrusion, failure, or accident

Intrusion

An attack on a network for purposes of gaining access to or destroying privileged information, or disrupting services to legitimate users

Network Architecture

A definition of the high-level behavior of and connections among nodes in a network, sufficient to evaluate network properties

Non-Essential Services

Services to users of a system that can be temporarily suspended to permit delivery of essential services while the system is dealing with intrusions and compromises.

Recognition Services

Survivable system functions that detect attempted and successful intrusions

Recovery Services

Survivable system functions that restore full services after an intrusion has occurred

Resistance Services

Survivable system properties and functions that make intrusion difficult and costly

Survivability

The capability of a system to fulfill its mission, in a timely manner, in the presence of attacks, failures, or accidents

Survivability Requirements

The definition of essential services as well as resistance, recognition, recovery, and adaptation and evolution functions that are sufficient to achieve required levels of a system’s survivability

System Requirements

The definition of user requirements for system services and usage, for which survivability requirements can be defined

Unbounded Network

A network characterized by topology and functionality that cannot be determined, and by the absence of centralized administrative control