Security LevelThe combination of hierarchical classification and a set of non-hierarchical categories that represents the sensitivity of information.
security lifeThe time over which cryptographically protected data or other security processes have value. [After X9.67]
security managementIn network management, the set of functions (a) that protects telecommunications networks and systems from unauthorized access by persons, acts, or…
security measureA means by which a System Security Policy is enforced [CESG]. Note: A general term, covering technical, procedural and management aspects of security.
security mechanismThe logic or algorithm that implements a particular security enforcing or security relevant function in hardware and software [ITSEC].
security modelA mathematical or conceptual representation for specifying and proving system security [CESG].
security objectAn entity in a passive role to which a security policy applies [ECMATR46].
security operating procedures (SyOPs)Documentation specifying the procedures that are to be carried out by system users (including the System Administrator and operators) to uphold all…
Security PolicyThe set of laws, rules, and practices that regulate how an organization manages, protects, and distributes sensitive information.
security policy model (SPM)1. An informal presentation of a formal security policy model [POSIX.6]. 2. An informal presentation of a formal security policy model [TCSEC]. 3.
security range[The] highest and lowest security levels that are permitted in or on an information system (IS), system component, subsystem, or network. [INFOSEC-99]
security relevantThat which is not security enforcing, but must function correctly for the Target of Evaluation to enforce security [ITSEC].
Security Relevant EventAny event that attempts to change the security state of the system. Also, any event that attempts to violate the security policy of the system.
security requirementThe statement by the Departmental Security Officer (DSO) of the minimum standards to be met by a specific system and particular threats which are to be…
security safeguardsProtective measures and controls prescribed to meet the security requirements specified for an information system (IS).
Security ServiceA capability that supports one, or many, of the security goals. Examples of security services are key management, access control, and authentication.
security specificationDetailed description of the safeguards required to protect an information system (IS). [INFOSEC-99]
security sub-domainA proper subset of a security domain's entities which are subject to a security policy which possesses the following properties: 1.
security subjectAn entity in an active role to which a security policy applies [ECMATR46].
security target (ST)1. A set of security functional and assurance requirements and specifications to be used as the basis for evaluation of an identified product or system. 2.
security test and evaluationExamination and analysis of the safeguards required to protect an information system (IS), as they have been applied in an operational environment, to…
Security TestingA process used to determine that the security features of a system are implemented as designed and that they are adequate for a proposed application…
security tokenA cryptographically signed data unit that expresses one or more claims.
SEEDBotanically, the matured ovule without accessory parts. Colloquially, anything which may be sown; i.e.
seed key[In INFOSEC, an] initial key, used to start an updating or key generation process. [INFOSEC-99]
seekTo position selectively the access mechanism of a direct access [storage] device.
seek timeThe time required for the access arm of a direct-access storage device to be positioned on the appropriate track. Synonym positioning time.
SegmentA grouping of elements that are closely related and often physically interface. It consists of CIs produced by several contractors and integrated by one.
segmented encoding lawAn encoding law in which an approximation to a curve defined by a smooth encoding law is obtained by a number of linear segments.
segregationFor genes, the separation of allele pairs from one another and their resulting assortment into different cells at meiosis.
seizingThe temporary dedication of various parts of a communications system to a specific use, usually in response to a user request for service.
seizure signalIn telephone systems, a signal used by the calling end of a trunk or line to indicate a request for service.
selcallAcronym for selective calling. Calling from one station in which call identification is sent to signal automatically one or more remote stations and to…
selected networkFor a particular message path, any intermediate network between a branch point and a subsequent branch point or convergence point is a selected network.
selective ringingIn a party line, ringing only the desired user instrument. Note: Without selective ringing, all the instruments on the party line will ring at the same…
SelectivityRefers to choosing a subset of targets either for attack or defense. (See Preferential Defense and Preferential Offense.)
self-authenticationA procedure in which a transmitting station , i.e., a calling station, establishes its own validity without the participation of the receiving station, i.
self-delineating blockA block in which a bit pattern or a flag identifies the beginning or end of a block.
self-focusingIn the optical regime, the property of an element (rod or slab of material) that (a) has a refractive index gradient that is a defined function of the…
self-relative addressIn computer programming, a partial computer address that uses the base address of the computer program, in which it appears, as the ellipsed component of…
self-synchronizing codeA code in which the symbol stream formed by a portion of one code word, or by the overlapped portion of any two adjacent code words, is not a valid code…
self-testing circuitA circuit that uses the data it is retransmitting to perform tests on itself to ensure that it is transmitting properly, i.e.
semi-permanent connectionA connection established via a service order or via network management. [T1.627-1993]
semiautomatic switching systemIn telephone systems, a switching system in which telephone operators receive call instructions orally from users and complete them by automatic equipment.
senderA device that accepts address information from a register or routing information from a translator, and then transmits the proper routing information to a…
sending loudness rating (SLR)The ratio in dB of the sound pressure produced by a speaker to the voltage produced by a telephone and loop as defined by ITU-T Recommendation P.79. [T1.
sending-end crossfireIn teletypewriter (TTY) systems, interference, in a given channel, caused by transmissions from one or more adjacent TTY channels transmitting from the…
sensitive information1. Information, the loss, misuse, or unauthorized access to or modification of, which could adversely affect the national interest or the conduct of…
SensitivityWhen referring to a medical test, sensitivity refers to the percentage of people who test positive for a specific disease among a group of people who have…
sensitivity label1. Information representing elements of the security label(s) of a subject and an object.
sensorA device that responds to a stimulus, such as heat, light, or pressure, and generates a signal that can be measured or interpreted.
SentinelABM system designed for light area defense against a low-level ballistic missile attack on the United States.
separate channel signalingSignaling in which the whole or a part of one or more channels in a multichannel system is used to provide for supervisory and control signals for the…
separation of dutiesIn secure communications, dividing responsibility for sensitive information so that no individual acting alone can compromise the security of the data…
separationsThe process by which telecommunication property costs, revenues, expenses, taxes, and reserves are apportioned among the operations. [47 CFR Pt.36-A]
septetA byte composed of seven binary elements. Synonym seven-bit byte.
sequenceThe linear order of nucleotides along a DNA or RNA molecule, and the process of obtaining this.
sequence number (SEQ)In a packet, a field of the packet header that is used by the terminating endpoint to determine if the packets arrive in sequence. [T1.509-1995]
sequential logic elementA device that has at least one output channel and one or more input channels, all characterized by discrete states, such that the state of each output…
serialPertaining to a process in which all events occur one after the other; for example, the serial transmission of the bits of a character according to the…
serial accessPertaining to the sequential or consecutive transmission of data into or out of a device, such as a computer, transmission line, or storage device. 2.
serial computerA computer that has a single arithmetic and logic unit. 2. A computer, some specified characteristic of which is serial; for example, a computer than…
serial portA port through which data are passed serially, i.e., one bit at a time, and that requires only one input channel to handle a set of bits, e.g.
serial transmissionThe sequential transmission of the signal elements of a group representing a character or other entity of data.
serial-to-parallel conversionConversion of a stream of data elements received in time sequence, i.e., one at a time, into a data stream consisting of multiple data elements…
series T junctionA three-port waveguide junction that has an equivalent circuit in which the impedance of the branch waveguide is predominantly in series with the…
ServerAny computer on a network that contains data or applications shared by users of the network on their client PCs.
server application processAn application process that implements all or part of the functionality defined by a service definition [ECMATR46].
service accessIn personal communications service (PCS), the ability for the network to provide user access to features and to accept user service requests specifying…
service access code (SAC)A 3-digit code in the (NPA) numbering plan area (N) format, which are used as the first three digits of a 10-digit address in a North American Numbering…
service access point (SAP)A physical point at which a circuit may be accessed. 2. In an Open Systems Interconnection (OSI) layer, a point at which a designated service may be…
service affecting limit (SAL)A parameter value consistent with minimum service objectives that are necessary to support high-speed modems.
service availabilityOf a virtual connection section, the long-term percentage of scheduled service time during which that section is available. [After T1.504-1989]
service bitA system overhead bit used for providing a network service, such as a request for a repetition or for a numbering sequence.
service codeA two-digit code used in the EC-to-IC (exchange carrier-to-interexchange carrier) facility/service selective signaling protocol and the IC-to-EC…
service controlDirection of the functions or processes used to provide a specific telecommunications service. [T1.667-1999]
service data unit (SDU)In layered systems, a set of data that is sent by a user of the services of a given layer, and is transmitted to a peer service user semantically…
service featureIn telephony, any of a number of special functions that may be specified initially, or added to, the user's basic service.
service identificationThe information that uniquely identifies an NS/EP telecommunications service to the service vendor and the service user.