War dialing or wardialing was a technique in the 1980s and '90s by which a computer would repeatedly dial a number (usually to a crowded modem pool) in an attempt to gain access immediately after another user had hung up.

The term (and the technique) pre-date the movie WarGames by several years. However, the popularity of the film among computer enthusiasts led to the term being commonly used for what is more precisely known as demon dialing, which figures prominently in the movie. The expansion of accessible ISP connectivity since that time more or less rendered the practice obsolete, and today "war dialing" much more frequently refers to demon dialing.

An identical technique was sometimes used to get the first call for prizes in radio "call-in" shows, thus leading to the adoption of random "fifth caller," "seventeenth caller" etc. by radio stations to circumvent this practice.

Toneloc was a famous piece of war dialing software for MS-DOS.

The term is also used today by analogy for various sorts of exhaustive brute force attack against an authentication mechanism, such as a password. While a dictionary attack might involve trying each word in a dictionary as the password, wardialing the password would involve trying every possible password.

See also

• war driving
• demon dialing

External link

• Wargames, Wardialing, Wardriving, and the Emerging Market for Hacker Ethics http://ssrn.com/abstract=585867