▁designed ▁to ▁serve ▁as ▁an ▁educational ▁exercise ▁to ▁give ▁participants ▁experience ▁in ▁se cur ing ▁a ▁machine , ▁as ▁well ▁as ▁conduct ing ▁and ▁react ing ▁to ▁the ▁sort ▁of ▁attacks ▁found ▁in ▁the ▁real ▁world ▁( i . e ., ▁bug ▁b ount y ▁programs ▁in ▁professional ▁settings ). ▁Re verse - engine ering , ▁network ▁sn iff ing , ▁protocol ▁analysis , ▁system ▁administration , ▁programming , ▁and ▁crypt analysis ▁are ▁all ▁skills ▁which ▁have ▁been ▁required ▁by ▁prior ▁C TF ▁cont ests ▁at ▁DE F ▁CON . ▁There ▁are ▁three ▁main ▁styles ▁of ▁capture ▁the ▁flag ▁compet itions : ▁attack / def ense , ▁hardware ▁challeng es ▁and ▁Je op ard y !. ▁ ▁In ▁an ▁attack / def ense ▁style ▁competition , ▁each ▁team ▁is ▁given ▁a ▁machine ▁( or ▁a ▁small ▁network ) ▁to ▁defend ▁on ▁an ▁isolated ▁network . ▁Teams ▁are ▁scored ▁on ▁both ▁their ▁success ▁in ▁def ending ▁their ▁assigned ▁machine ( s ) ▁and ▁on ▁their ▁success ▁in ▁attack ing ▁the ▁other ▁team ' s ▁machines . ▁Depending ▁on ▁the ▁nature ▁of ▁the ▁particular ▁C TF ▁game , ▁teams ▁may ▁either ▁be ▁attempting ▁to ▁take ▁an ▁oppon ent ' s ▁flag ▁from ▁their ▁machine ▁or ▁teams ▁may ▁be ▁attempting ▁to ▁plant ▁their ▁own ▁flag ▁on ▁their ▁oppon ent ' s ▁machine . ▁Two ▁of ▁the ▁more ▁prominent ▁attack / def ense ▁C TF ' s ▁are ▁held ▁every ▁year ▁at ▁DE F ▁CON , ▁the ▁largest ▁ha cker ▁conference , ▁and ▁the ▁NY U -