On current code, if the FID matches, you don't need the archive's password. Generally it depends a little on when (i.e. with which client build) the archive has been touched. If it was a GW2014 or later build, the following would apply:
- you can simply rename the archive path name and access the archive as someone else provided you know the password of the archive
- if you create a user with the FID of the archive this user can access the archive without knowing the password. The user's name does NOT have to match, it's just about the FID.