Peachpit Learning Series Mac OS X 10.4 Tiger [Electronic resources] نسخه متنی

Know Your Security Options

There are several kinds of

security features on your Mac. One set of features is to protect you from bad things that come in through the Internet or another network. Apple has installed lots of security stuff on your Mac, things like Kerberos, Secure Shell, Wired Equivalent Privacy data encryption, Virtual Private Network, firewalls, and other features. It doesn't matter to most of us what those arethey work behind the scenes. Your Software Update (one of the System Preferences) will automatically update security features as Apple releases them.164. A .Mac membership includes the software Virex to combat the evil buggers.

Passwords on your Mac

You have several different passwords on your Macintosh.

• Administrator password :
  When you first turn on your Mac, you are asked to create a password. Write this down in a safe place! You will need this password whenever you install new software or when you make certain system-wide changes.

  

  You can choose

  not to have a password. Your Mac will still

  ask you to enter a password, howeverif you never entered one, just leave the password field blank, and click the ok or "Continue" button.

If you forget this Admin password, you will need to reset it

• Login password :
  If you have set up multiple users on one Mac, each user has her own password to log in.

  An Admin password is also the login password for that Admin user . By default, your Mac is set to auto-login the Admin so you don't need your password at startup (you can turn this off).

  If a standard user forgets his password: The Administrator (or anyone who knows the Admin password) can reset the user password in the Accounts preferences.

• Keychain Access password :
  This is the same as the login password, whether you are a standard user or the Admin (you can change it to create a special keychain password). Keychain Access is the application on your Mac that keeps track of a variety of passwords for you. If you can remember your login password, then Keychain Access can show you the rest of your passwords. See pages 160161.

• Master password :
  An Administrator can set up a computer-wide password in case he forgets the login password. Master passwords are usually used in conjunction with FileVault; see pages 162163. The Admin's Master password can override a standard user's FileVault password.

  What to do if you forget the Master password? Well, you can scream. It won't help, but you can scream. See page 162.

Password tips

• A password should be difficult for others to guess, but easy for you to remember.

• Don't use a word that can be found in a dictionary. Some hackers use software that tries every word in the dictionary in a matter of minutes.

• Combine caps and lowercase and numbers.

• Most passwords are case-specific, meaning a lowercase "r" is completely different from an uppercase "R." Take advantage of this and put capital letters where someone wouldn't expect them.

Low-level security features

• Turn off auto-login :
  Auto-login lets your Mac start up without a passwordit automatically logs in the person who has "auto-login" turned on in the Accounts preferences (click "Login Options" at the bottom of the list of accounts).

  Then be sure to

  log out before you leave your computer for a while. This ensures that people walking by will need a password to log back in to your account, even if they restart your Mac. Laptops should always require a login password.

  

• If you don't want to turn off auto-login , you might want to take the extra step to uncheck the box to "Show the Restart, Sleep, and Shut Down buttons." Because if auto-login is on and you log out, the login screen appears. But someone can just click the Restart or Shut Down button, and the computer starts back up again and automatically logs into your account.

  This precaution isn't going to help much if your laptop is stolen because someone can just reboot the computer. Nor will it help if the Restart button is accessible on your desktop machine!

• Mac OS X lets you have multiple users on one computer, and each user has a separate, private Home area (see Lesson 9 for details). Even if you are the only one using this Mac, you can

  create another user, a standard user who has no administrative privileges, and log in as the standard one. This is a simple step that just makes it one level more difficult for someone to get into your main account and make system-wide changes. It won't protect any data that you create as that user, but it will make it more difficult to get to any data you create as the Administrator.

To prevent access to anyone walking by your computer, you can use these simple yet effective features:

• Use the Security preferences to

  require a user/Admin password to wake up the Mac from sleep or from the screen saver. Remember, to get to a system preference such as Security or the ones mentioned below, go to the Apple menu and choose "System Preferences…."

  Then go to the "Desktop & Screen Saver" preferences to choose a screen saver and tell it when to start.

  Then go to the "Energy Saver" preferences to tell your Mac to put either the computer and/or the display (the screen) to sleep after a certain amount of time.

• An alternative to the above technique is to set up your Mac so you can

  lock it with a mouse click whenever you choose, not just when the screen saver comes on or when it goes to sleep.

To lock your Mac with a click

Higher-level security features

• Secure Empty Trash :
  You might think that after you empty the Trash, it's gone. But it's possible to recover many deleted files using special data-recovery software. If you are selling or giving away your Mac, you might want to make sure no one can recover your old, trashed files. To completely overwrite files so no one can ever get to them, go to the Finder menu and choose

  Secure Empty Trash. This might take several minutes, depending on how much stuff you've thrown away since you got the computer!

• Encrypt a disk image :
  Using the Disk Utility (found in the Utilities folder, which is in the Applications folder), you can protect all or part of your hard disk by making a selected portion of it into a "disk image," which looks like a hard disk icon. It has its own password; if your Keychain is locked (see pages 160161), this image is really safe from prying eyes and fingers because someone would need both passwords to access the disk. When unlocked, this disk image acts just like any other hard disk and you can move files in it, copy files to it, and delete files from it. I recommend you read all about this feature in the Disk Utility Help files before you start using it.