The Internet is becoming an essential part of our lives. This trend is even stronger with the rise of cell phones having Internet access that almost the entire population carries with them at all times. Security is a huge problem on the Internet, however, and new authentication methods are needed specifically for cell phones. Presented here is a method of identifying a mobile electronic device by its configuration settings, potentially including contact list information. This invention, in particular, fills a crucial need to secure access to the Internet from mobile phones.