The official DEF CON Archive is a massive collection of hacker history.
The DEF CON Media Server acts as the official repository for every presentation, tool, and piece of media generated by the conference. Unlike many corporate security conferences that charge thousands of dollars for access to their archives, DEF CON remains committed to the principle that information should be free. Key Content in the Archive: defcon archive
If you are looking for a solution to a specific "Archive" challenge, it likely refers to one of these from the Order of the Overflow (OOO) Archive : The official DEF CON Archive is a massive