O

off-site storage

Storing data offsite, usually in a secure location.

one-tier model

A model in which the database and application exist on the same system.

one-time pad

Words added to values during authentication.

onsite storage

Storing backup data at the same site as the servers on which the original data resides.

Open Shortest Path First

A Link-State routing protocol used in IP networks.

Open Systems Interconnect (OSI)

A model defined by the ISO to categorize the process of communication between computers in terms of seven layers. The seven layers are Application, Presentation, Session, Transport, Network, Data Link, and Physical. See also International Organization for Standardization.

operational security

Security as it relates to how an organization does things (operates).

operator

The person primarily responsible for the IDS.

OS hardening

The process of applying all security patches and fixes to an operating system to make it as secure as possible.

OSI

See Open Systems Interconnect.

OSPF

See Open Shortest Path First.

Out-of-Band method

A way to transmit the encryption key by using a method other that the one used to transmit the data. The key is sent by letter, by courier, or by some other separate method.

owner

The person responsible for the current existence of a resource.