Wireless and Mobile Device Security, 2nd Edition

Cookies

As noted, a website creates a cookie when a user first visits. When a device returns to the website, it passes along the cookie for that site. The website then recognizes the cookie’s unique identifier, which identifies the user.

The cookie itself is a simple file containing information stored as sets of name-value pairs—for example, userID/A9CF87546ABC, where the name of the pair is userID and the value is A9CF87546ABC. Most websites create cookies that store this information and nothing else. This is not because they care about the user’s privacy, but because it isn’t practical to store the user’s information on the user’s device. That’s mostly because websites store a lot more about the user than just the name-value pair. Some common ...