L

L2F (Layer 2 Forwarding Protocol)

A VPN protocol similar to PPTP.

L2TP (Layer 2 Tunneling Protocol)

A VPN protocol similar to PPTP and L2F.

LAN

Local area network.

Lattice-based access controls

A method for implementing mandatory access controls in which a mathematical structure defines greatest lower-bound and least upper-bound values for a pair of elements: for example, subject and object.

LDAP (Lightweight Directory Access Protocol)

An IP protocol and data storage model that supports authentication and directory functions.

Least privilege

A principle requiring that a subject is granted only the minimum privileges necessary to perform an assigned task.

Link encryption

Packet encryption and decryption at every node along the network path. Requires each node to have separate key pairs for its upstream and downstream neighbors.

Logic bomb

A program, or portion thereof, that is designed to perform some malicious function given the realization of a predetermined circumstance.