Cabbage (DayZ)

Well I downloaded the mod right form the site followed all the instructions in the video. Also when I look in the folder the two files are not there nor are they in the download section. The files I have in the @DayZ\addons are: dayz.pbo.dayz.bisign dayz_anim.pbo.dayz.bisign dayz_code.pbo.dayz.bisign dayz_equip.pbo.dayz.bisign dayz_sfx.pbo.dayz.bisign dayz_vehicles.pbo.dayz.bisign dayz_weapons.pbo.dayz.bisign dayz.pbo dayz_anim.pbo dayz_code.pbo dayz_equip.pbo dayz_sfx.pbo dayz_vehicles.pbo dayz_weapons.pbo In game menu also says arma 2 @dayz so I think I have it installed right. Just cant join any games. Is there a way to play single player?

Hello all I am trying to get this mod to run but I'm having some problems. Every server I try and join gives me this message. Files "c:\program files (x86)\steam\steamapps\common\arma2\addons\chu_undead.pbo", "c:\program files (x86)\steam\steamapps\common\arma2\addons\chn_undead_misc.pbo" are not signed by a key accepted by this server. To play on this server, remove listed files or install additonal accepted keys. Any one got any Ideas on how I can get this mod work? Thanks.