Ask Max: .dmg File No Longer Requires Password
I have a few disk images (.dmg) which I have password protected to protect sensitive information. After working OK for a couple of years, one of my .dmg's has suddenly stopped requiring a password to open it, while my other .dmg's remain as they were i.e., still require passwords to open. I have my Macs connected via a home Wi-Fi network as well as synced by .Mac. The peculiar thing is that the .dmg that has suddenly lost the need for a password has done it on both my Macs.
I have rebooted both machines but the problem persists. Any ideas?
This is often caused by an inadvertent selection of the "remember Password in Keychain option." Also .Mac supports Keychain syncing, so if you had one computer's Keychain remember the password, both computers will have the same info. The fix should be simple. Go to the application "Keychain Access" in your Utilities folder. Search for your disk image's name or just browse through the "All Items" category. After you find your password for the disk image, select it and then delete it. You will then be prompted for the password again when mounting the disk image. You may have to repeat this process on all your computers to avoid the password being recovered from .Mac syncing.