The first DEF CON hacker conference was held in 1993.
Jeff Moss organized the event in Las Vegas as a farewell party before moving away from the area. The name combined “DEF,” a reference to the DEFCON military readiness scale, with “CON,” meaning conference. What began as a small gathering grew into one of the world’s best-known hacker conventions.
DEF CON typically includes talks, technical villages, contests, workshops, and demonstrations. Participants range from security researchers and professional penetration testers to hobbyists, students, government personnel, and journalists. Its culture emphasizes hands-on learning and debate about computer security.
DEF CON is not the same event as Black Hat. Black Hat began in 1997 as a more formal security conference, while DEF CON retained a more informal hacker-convention identity. Although the event is associated with Las Vegas, its technical influence extends internationally through presentations, tools, and research shared by attendees.