Glossary of Key Information Security Terms (NIST) part 29 / H - I

Hardening –

Hardening –

Configuring a host’s operating systems and applications to reduce the host’s security weaknesses.

Hardware –

The physical components of an information system. See also Software and Firmware.

Hardwired Key –

Permanently installed key.

Hash Function 1 –

A function that maps a bit string of arbitrary length to a fixed length bit string. Approved hash functions satisfy the following properties: 1) One-Way. It is computationally infeasible to find any input that maps to any prespecified output. 2) Collision Resistant. It is computationally infeasible to find any two distinct inputs that map to the same output.

Hash Function 2 –

A mathematical function that maps a string of arbitrary length (up to a predetermined maximum size) to a fixed length string. A function that maps a bit string of arbitrary length to a fixed length bit string. Approved hash functions are specified in FIPS 180 and are designed to satisfy the following properties: 1. (One-way) It is computationally infeasible to find any input that maps to any new prespecified output, and 2. (Collision resistant) It is computationally infeasible to find any two distinct inputs that map to the same output.

Hash Total –

Value computed on data to detect error or manipulation. See Checksum.

Hash Value –

The result of applying a cryptographic hash function to data (e.g., a message).

Hash-based Message Authentication Code – (HMAC)

A message authentication code that uses a cryptographic key in conjunction with a hash function. A message authentication code that utilizes a keyed hash.

Hashing –

The process of using a mathematical algorithm against data to produce a numeric value that is representative of that data.

Hashword –

Memory address containing hash total.

Health Information Exchange – (HIE)

A health information organization that brings together healthcare stakeholders within a defined geographic area and governs health information exchange among them for the purpose of improving health and care in that community.

High Assurance Guard (HAG) –

An enclave boundary protection device that controls access between a local area network that an enterprise system has a requirement to protect, and an external network that is outside the control of the enterprise system, with a high degree of assurance. A guard that has two basic functional capabilities: a Message Guard and a Directory Guard. The Message Guard provides filter service for message traffic traversing the Guard between adjacent security domains. The Directory Guard provides filter service for directory access and updates traversing the Guard between adjacent security domains.

High Availability –

A failover feature to ensure availability during device or component interruptions.

High Impact –

The loss of confidentiality, integrity, or availability that could be expected to have a severe or catastrophic adverse effect on organizational operations, organizational assets, individuals, other organizations, or the national security interests of the United States; (i.e., 1) causes a severe degradation in mission capability to an extent and duration that the organization is able to perform its primary functions, but the effectiveness of the functions is significantly reduced; 2) results in major damage to organizational assets; 3) results in major financial loss; or 4) results in severe or catastrophic harm to individuals involving loss of life or serious life threatening injuries).

High-Impact System –

An information system in which at least one security objective (i.e., confidentiality, integrity, or availability) is assigned a FIPS 199 potential impact value of high. An information system in which at least one security objective (i.e., confidentiality, integrity, or availability) is assigned a potential impact value of high.

Honeypot –

A system (e.g., a Web server) or system resource (e.g., a file on a server) that is designed to be attractive to potential crackers and intruders and has no authorized users other than its administrators.

Hot Site –

A fully operational offsite data processing facility equipped with hardware and software, to be used in the event of an information system disruption. Backup site that includes phone systems with the phone lines already connected. Networks will also be in place, with any necessary routers and switches plugged in and turned on. Desks will have desktop PCs installed and waiting, and server areas will be replete with the necessary hardware to support business-critical functions. Within a few hours, a hot site can become a fully functioning element of an organization.

Hot Wash –

A debrief conducted immediately after an exercise or test with the staff and participants.

Hybrid Security Control –

A security control that is implemented in an information system in part as a common control and in part as a system-specific control.

IA Architecture –

A description of the structure and behavior for an enterprise’s security processes, information security systems, personnel and organizational sub-units, showing their alignment with the enterprise’s mission and strategic plans.