subject

1. In cryptography, an entity whose public key is certified in a public key certificate. 2. Generally, a person, process, or device, causing information to flow among objects or change to the system state. [INFOSEC-99]3.An active entity, generally in the form of a person, process, executing program or device that causes information to flow among objects or changes the system state. Examples: process, executing program [CESG].See also: Object.4.Abbreviation of security subject [ECMATR46].5.an active entity, generally in the form of a person, process, or device[ITSEC].6.An active entity that causes information to flow between objects or changes the system state; a process [POSIX.6].7.An active entity, generally in the form of a person, process, or device that causes information to flow among objects or changes the system state. Technically, a process/domain pair [TCSEC].