quadrant: Short name referring to technology that provides tamper-resistant protection to cryptographic equipment. SOURCE: CNSSI-4009

qualitative assessment: Use of a set of methods, principles, or rules for assessing risk based on nonnumeric categories or levels. SOURCE: SP 800-30

quality of service: The measurable end-to-end performance properties of a network service, which can be guaranteed in advance by a Service-Level Agreement between a user and a service provider, so as to satisfy specific customer application requirements. These properties may include throughput (bandwidth), transit delay (latency), error rates, priority, security, packet loss, packet jitter, and so forth. SOURCE: CNSSI-4009

quantitative assessment: Use of a set of methods, principles, or rules for assessing risks based on the use of numbers where the meanings and proportionality of values are maintained inside and outside the context of the assessment. SOURCE: SP 800-30

quarantine: Place files containing malware in isolation for disinfection or future examination.