Encryption is a method of encoding afile so that the data cannot be read without knowing the mathematical equationused to encode the file. When you encrypt a file, its data can only be read ifthe program that encrypted it is available and you know the correct password.
Why should I care about encryption?
Just because your computer is protected by a login password doesn't mean that your files are safe from prying eyes. If your computer was stolen, the operating system's login screen can be easily bypassed, and there is nothing to prevent data from being read straight off your drive on another computer. The only way to prevent unwarranted access to your data is to encrypt it.
However, if you happen to lose the password or passphrase, you will never be able to open that file again. It is also important to note that encryption can make data less resilient to any corruption that could happen in underlying parts of the computer's storage systems. You should be doing so anyway, but make absolutely sure you are backing-up your files.
What should I be encrypting?
You should encrypt any file that you wouldn't want to print on a t-shirt and wear while walking down the street. Financial data, bank information, health and medical records should all be protected by encryption. If you have a list of your usernames and passwords for your various accounts around the web, this should definitely be encrypted.
The safest thing to do is to encrypt your entire hard drive. If that isn't feasible, encrypting your entire drive isn't feasible, encrypting your home folder is better than nothing. If that isn't feasible as well, then you should at least be encrypting your most important and sensitive files. If answering the question, "Should I encrypt this file?" takes more than a split-second, the answer is probably yes. And if a file is worth encrypting, it is certainly important enough to warrant backing-up.
How do I encrypt something?
Files, folders, and even entire hard drives may be encrypted. However, anything that is encrypted is lost if you should forget the password, so it is important to only encrypt that which really needs to be encrypted.
Files: Encrypting a file no one may view or change that file unless they possess the pass word or phrase. This is a good idea for files containing important data such as other passwords, financial information, or other such data that you would never want leaked.
- Windows: AxCrypt is a free program available online. Windows also has a feature called Encrypting File Systems (EFS) which comes with editions of Windows above Home (e.g. Enterprise, Ultimate, etc.). Instructions for using Microsoft EFS may be found on the Microsoft website.
- Mac OS X: Mac 10.3 and higher come with the ability to encrypt files using the Disk Utility to create a Disk Image. Instructions on how to do this may be found on the Mac Support page.
Home Folder: By encrypting your home folder, you ensure that no one other than yourself may access any of its contents. The Home folder is specific to each user on the computer, so encrypting it allows other users to still log on without a pass phrase, while allowing you to encrypt most of the data important to you specifically.
- Windows: More recent versions of Windows have BitLocker, an encryption program that comes with the operating system. For more information on how to use BitLocker, see the Microsoft page.
- Mac OS X: Macs prior to OS 10.7 (Lion) come with an encryption program called FileVault which can encrypt your home folder. As of 10.7, Filevault is replaced by Filevault2, which encrypts the entire disk. See details below.
Full Disk Encryption: It is possible to encrypt an entire hard drive. This encrypts the entire computer, meaning that the machine will require a password or pass phrase before starting.
If you lose the pass word or phrase, your computer will need to be reformatted and all data will be lost! However, despite the risks associated with full drive encryption, it is the best way ensure that all your data is secure.
- Whitman Computers: If you wish to encrypt the hard drive of a Whitman-owned computer, please contact WCTS.
- Personal Windows Computer: For your personal Windows computer, the best option for full drive encryption is TrueCrypt. The software is available free online.
- Personal Mac OS X Computer: Full-disk encryption is available as of Mac OS 10.7 (Lion). See the Apple Support page for Filevault2 for details.
Note: Due to the fragile nature of full drive encryption, it is critical to backup your files. See our Backing up your Files page for more information.