EM, security> An operating systEM security or access control model where specific types of access to a specific object are granted by giving a process this data structure or token. The token may be unforgeable (typically by using encryption or hardware "tagged" mEMory). Capabilities are used in OSes such as Hydra, KeyKOS, EROS, Chorus/Mix, and the Stanford V systEM. Similar to Kerberos, but in an OS context. Compare access control list. (1998-03-08)