I think reading this explains it all : https://community.bistudio.com/wiki/ArmA:_Addon_Signatures

Bikey's are there to stop hackers, as it allows server admins to restrict what addons can be used on there server. This can be disabled by setting | verifySignatures = 0| and then all mods are allowed.

This causes hardly any problems for the host and is as simply as dropping a key from the addon maker into a folder.