To encrypt means to put into code or cipher. You may have made codes with friends when you were younger. You would have your message, then you would make a code. Maybe you moved every letter over one. An A would become a B. To decode it, the recipient would have to move the letters back one. That was a form of encryption. But encryption can be much more secure than that.
Encryption has been around for millennia. Julius Caesar used it to protect documents from the messengers delivering the documents. Although that wasn’t very secure, it still was encrypted. We still have problems today. Networks of computers are very dangerous, in the security sense. People use encryption to protect their documents.
People encrypt files so others can’t see them. A hacker will hack into a computer to read, and possibly copy, other peoples e-mail and files. However, any self-respecting hacker will not delete the files. For the most part, they will hack into mainframe style computers. These are all run on command line interfaces. Since hackers use terminal software to hack (ZTerm, Communications part of ClarisWorks, etc.) into a computer, it is very hard (impossible?) to hack into a Mac, simply because it does not have a command line interface.
There are two main styles of encryption. The first is the secret key type. In this style, there is one key. My opening example was a secret key. If anyone found the key, they could decode all the messages. You can still use this type, but only you and the person your sending to can know the code.
The second style is public key encryption. With this, there are two keys. One of them, the public key, encodes the message. The second key, or the private key, decodes the message. The public key is meant to be given out to the world. It cannot decode a message. The private key, however, is only to be used by you. If that goes out to anyone, your files aren’t safe. If you keep your private key to yourself, this is the best type of encryption.
Pretty Good Privacy, known as PGP, is a two key system. The privacy is a lot more than “pretty good,” though. The US government had some problems with PGP. They were afraid terrorist groups, drug lords, etc. might use it to encrypt e-mail to plan their next move. The fact that PGP was free didn’t help either. Soon after its release, it was uploaded to the Internet. Now people were getting it in other countries. The government was thinking about pressing charges against Philip Zimmerman, the creator of PGP. They were doing this because they thought he had uploaded it to the Internet. When, in fact, he had not. The government never did press any charges and never said if they could decrypt PGP or not. It is illegal to download PGP or obtain it without a license if you do not live in the US.
PGP is used for coding e-mail. There is no point in trying to code files on your hard drive. You will have to have both keys on the same drive anyway. Unless you kept your private key on a floppy and hid it. But the main use of PGP is for e-mail privacy. If you want to protect your files on your hard drive, you probably need some sort of password protection.
One of the most known and widely used protectors for the Mac is At Ease. Every store will have this installed. It simplifies the whole Finder into Launcher-esque buttons on pages. It is customizable from the Finder. The owner, administrator, of the Mac can set a password so only they can go to the Finder. The administrator also can setup profiles for each user that will be using the Mac. Each one has their own password and their own set of files and programs they can use. Unless someone figures out the administrator’s password, they are forced to stay in the protected At Ease.
But there are ways to bypass At Ease. The most common is to restart from the System disk. Another is if someone figures out the administrator’s password. When you get this, you have full access to the Finder and you can modify the profiles of At Ease users. That includes changing of passwords. The best way to prevent this is to use a very strange phrase with characters like: @, !, $, etc. You should also change the password regularly.
Another way to break At Ease is to use the Interrupt Switch. Somewhere on your Mac is a pair of two buttons. On compact Macs, they should be out on the side. On some Quadras and PowerMac 6100’s they are on the back. Look in the setup manual that came with your Mac for more specific areas. If you can’t find any switches, try using these key combinations: Cmd+cntrl+power key is the Reset Switch. Cmd+power key is the Interrupt Switch.
Assuming you have the buttons, the one marked with a little triangle (like the power key) is the Reset Switch. This restarts your Mac. The only time this is used is after a crash and all you can do is turn the computer off. Use this rather than turning the power off and on. Next to that button is another one with a dot on it. This is the Interrupt Switch. When this is pressed, a box comes on the screen with a “>” in it. If you type “G FINDER” into this box it will go to the Finder. This still works in At Ease. You still won’t learn the administrators password, but you will be back in the Finder.
Security is a very important thing on computers. Many people have very important documents on a computer that aren’t protected. You don’t realize it, but people can read your e-mail and use information against you. Obviously, the best way to stay protected is to not connect to other computers and monitor who uses your Mac. But this isn’t always possible. Some programs have a built-in password feature. I think WordPerfect and Excel both have this feature. But to anyone dedicated, these are not hard to crack. The best advice I can give is to use common sense. If you don’t want people reading your e-mail, insist on using PGP. If you don’t want people opening a file, don’t keep it on your hard drive. If you use your head, there will be no trouble at all.