As we saw in Chapter 6, passwords are the simplest form of authentication. Passwords are a secret that you share with the computer. When you log in, you type your password to prove to the computer that you are who you claim to be. The computer ensures that the password you type matches the account that you have specified. If they match, you are allowed to proceed.
Using good passwords for your Internet services is a first line of defense for your privacy. If you pick a password that is easy to guess, then somebody who is targeting you will find it easier to gain access to your personal information. If you use the same password on a variety of different services, then a person who is able to discover the password for one of your services will be able to access other services.
Historically, most desktop personal computers did not use passwords. PCs were designed for use by a single person; in this environment, passwords were seen as an unwanted hassle.
If you are like most computer users, you probably got your first password when you got your first Internet email account: your password prevented other people from logging in to your Internet account and downloading your email. As your use of the Web grew, you were probably asked to create accounts on various web sites. For example, if you buy a book from Amazon, the Amazon web site will ask you for a password so that other users will not be able to view the books you have ordered.
Over the years, ...