In anticipation of the official release of the incredible ARMA2 OA v1.60 patch with v2 signatures and countless other MP and general improvements,
As of today, all mods on the official Six Updater network are signed with v2 bisigns. (That's over 250 mods!)
As a result, most of the Mods will show there are updates available, no worries, bikey+bisigns are very small :)
All future mods will also be signed with v2 if unavailable.
Original signatures remain usable and untouched, however v2 signatures improve security over the older and long used v1 signatures,
Servers are recommended to enable and accept v2 signatures only (verifySignatures = 2;), and BattlEye enabled (battlEye = 1;), combined for best results.
Server bikeys can also be downloaded directly from the Six Updater Portal, Mods section.
For more info about signature/battleye protection, check out this blog entry.
Reminder: Report ARMA2 issues to the Community Issue Tracker.