A block of data sent over the network transmitting the identities of the sending and receiving stations, error-control information, and messages.
Inspects each packet for user-defined content, such as an IP address, but does not track the state of sessions. This is one of the least secure types of firewall.
A feature incorporated into routers and bridges to limit the flow of information based on predetermined communications, such as source, destination, or type of service being provided by the network. Packet filters let the administrator limit protocol-specific traffic to one network segment, isolate e-mail domains, and perform many other traffic-control functions.
A device or program that monitors the data traveling between computers on a network.
An attack that does not result in an unauthorized state change, such as an attack that only monitors or records data.
The threat of unauthorized disclosure of information without changing the state of the system. A type of threat that involves the interception, not the alteration, of information.
Privacy Enhanced Mail—An IETF standard for secure mail exchange.
The successful unauthorized access to an automated system.
The description of a situation or set of conditions in which a penetration could occur or of system events that in conjunction can indicate the occurrence of a penetration in progress.
The portion of security testing in which the evaluators attempt to circumvent the security features of a system. The evaluators may be assumed to use all system design and implementation documentation, which may include listings of system source code, manuals, and circuit diagrams. The evaluators work under the same constraints applied to ordinary users.
The technique of securing a network by controlling access to all entry and exit points of the network; usually associated with firewalls or filters.
The entity from the external environment that is taken to be the cause of a risk. An entity in the external environment that performs an attack (i.e., a hacker).
The procedures established to ensure that all personnel who have access to any classified information have the required authorizations, as well as the appropriate clearances.
Pretty Good Privacy—A freeware program primarily for secure e-mail.
A program that modifies other programs or databases in unauthorized ways, especially one that propagates a virus or Trojan horse.
Phone book file demonstration program that hackers use to gain access to a computer system and potentially read and capture password files.
A well-known and vulnerable CGI script that does not filter out special characters (such as a new line) input by a user.
An individual who combines phone phreaking with computer hacking.
An individual fascinated by the telephone system. Commonly, an individual who uses his knowledge of the telephone system to make calls at the expense of another.
The art and science of cracking the phone network.
The measures used to provide physical protection of resources against deliberate and accidental threats.
The gaining of unauthorized access to a system via another user's legitimate connection.
The use of ping with a packet size higher than 65,507. This will cause a denial of service.
Unencrypted data.
An encryption methodology in which the encryptor and decryptor use the same key, which must be kept secret. This methodology is usually used only by a small group.
Any effort to gather information about a machine or its users for the apparent purpose of gaining unauthorized access to the system at a later date.
See Administrative Security.
Patterns of a user's activity that can detect changes in normal routines.
Normally an Ethernet interface reads all address information and accepts follow-on packets only destined for itself, but when the interface is in promiscuous mode, it reads all information (sniffer), regardless of its destination.
Agreed-upon methods of communications used by computers. A specification that describes the rules and procedures that products should follow to perform activities on a network, such as transmitting data. If they use the same protocols, products from different vendors should be able to communicate on the same network.
A daemon that is run periodically to seek out and erase core files, truncate administrative logfiles, nuke lost+found directories, and otherwise clean up.
A firewall mechanism that replaces the JP address of a host on the internal (protected) network with its own IP address for all traffic passing through it. A software agent that acts on behalf of a user. Typical proxies accept a connection from a user, make a decision as to whether or not the user or client IP address is permitted to use the proxy, perhaps does additional authentication, and then completes a connection on behalf of the user to a remote destination.
Planned operations to convey selected information and indicators to foreign audiences to influence their emotions, motives, objective reasoning, and ultimately the behavior of foreign governments, organizations, groups, and individuals. The purpose of psychological operations is to induce or reinforce foreign attitudes and behavior favorable to the originator's objectives (JP 1-02).
A type of cryptography in which the encryption process is publicly available and unprotected, but in which a part of the decryption key is protected so that only a party with knowledge of both parts of the decryption process can decrypt the cipher text.