Abstract :
Mobile phone users access content from websites using their browsers and are tracked by cookies. Users also access content using mobile applications, which are tracked by totally separate identifiers, ???device identifiers.??? Traditional approaches to tracking users fail to tie these two domains together. Hence, remote ???fingerprinting??? techniques have been suggested that extract set of attributes of a phone to create an almost unique identifier to track the phone user. We present a study of various fingerprinting techniques used at different layers of the networking protocol stack. We highlight the differences between fingerprinting computers and fingerprinting phones. Since fingerprinting is also a threat to user privacy, we present the current research and suggest future research directions in addressing the privacy issues.