45 C.F.R. § 164.304
As used in this subpart, the following terms have the following meanings:
Access means the ability or the means necessary to read, write, modify, or communicate data/information or otherwise use any system resource. (This definition applies to "access" as used in this subpart, not as used in subparts D or E of this part.)
Administrative safeguards are administrative actions, and policies and procedures, to manage the selection, development, implementation, and maintenance of security measures to protect electronic protected health information and to manage the conduct of the covered entity's or business associate's workforce in relation to the protection of that information.
Authentication means the corroboration that a person is the one claimed.
Availability means the property that data or information is accessible and useable upon demand by an authorized person.
Confidentiality means the property that data or information is not made available or disclosed to unauthorized persons or processes.
Encryption means the use of an algorithmic process to transform data into a form in which there is a low probability of assigning meaning without use of a confidential process or key.
Facility means the physical premises and the interior and exterior of a building(s).
Information system means an interconnected set of information resources under the same direct management control that shares common functionality. A system normally includes hardware, software, information, data, applications, communications, and people.
Integrity means the property that data or information have not been altered or destroyed in an unauthorized manner.
Malicious software means software, for example, a virus, designed to damage or disrupt a system.
Password means confidential authentication information composed of a string of characters.
Physical safeguards are physical measures, policies, and procedures to protect a covered entity's or business associate's electronic information systems and related buildings and equipment, from natural and environmental hazards, and unauthorized intrusion.
Security or Security measures encompass all of the administrative, physical, and technical safeguards in an information system.
Security incident means the attempted or successful unauthorized access, use, disclosure, modification, or destruction of information or interference with system operations in an information system.
Technical safeguards means the technology and the policy and procedures for its use that protect electronic protected health information and control access to it.
User means a person or entity with authorized access.
Workstation means an electronic computing device, for example, a laptop or desktop computer, or any other device that performs similar functions, and electronic media stored in its immediate environment.
45 C.F.R. §164.304