DEF CON Capture the Flag 2016

Legitimate Business Syndicate

We build innovative Capture the Flag games that pit hackers from around the world against the smartest analog adversaries and computerized challengers known.

The future of Capture the Flag is now, and it's never been brighter.

Thanks for the fun! Wish I had more time to solve the tougher challenges.


Online, free, and for security enthusiasts and hackers of any skill level. Registration open now!

Midnight UTC, May 21, 2016
Midnight UTC, May 23, 2016

Defcon had some of the evilest, trickiest challenges I've ever faced in a CTF. And it was super fun because of it.


Witness the top hackers in the world battle it out head-to-head live at DEF CON in Las Vegas.

August 5, 2016
August 7, 2016

+1 to this - the organizers was fantastic this year. Infrastructure was amazingly solid, the room environment was comfortable, and the organizers were very open with communication.

Qualifying for Finals

You can qualify for our finals in Las Vegas by winning one of several different competitions online and around the world, or placing well in our qualifiers held online May 21-23.

Contest Dates Notes
DEF CON CTF 2015 May 16 - Aug. 9 2015 Qualified DEFKOR
HITCON CTF Oct. 17 - Dec. 6 2015 b1o0p
RuCTFE Nov. 21, 2015 Qualified StratumAuhuur
SECCON CTF Dec. 5 2015 - Jan. 31 2016 Already qualified Cykorkinesis/DEFKOR
32C3 CTF Dec. 27 - 29 2015 Qualified pasten
Boston Key Party Mar. 4 - 6 2016 Qualified HITCON
PlaidCTF Apr. 15 - 17, 2016 LC↯BC
0ctf Mar. 12 - Apr. 24, 2016 Already qualified LC↯BC
DEF CON CTF 2016 Qualifiers May 21 - 23, 2016 Online Jeopardy style, qualifying multiple teams
DARPA Cyber Grand Challenge August 4, 2016 All-machine competition, on-site in Las Vegas

Legitimate Business Syndicate is proud to have run some of the most well-regarded hacking contests in the world.