Security and Usability

Chapter Thirty Three. Usability and Privacy: A Study of KaZaA P2P File Sharing

Nathaniel S. Good and Aaron Krekelberg

P2P FILE SHARING SYSTEMS SUCH AS GNUTELLA, FREENET, AND KaZaA, while primarily intended for sharing multimedia files, frequently allow other types of information to be shared. This raises serious concerns about the extent to which users may unknowingly be sharing private or personal information.^[1]

IIn this chapter, we report on a cognitive walkthrough and a laboratory user study of the KaZaA file sharing user interface. The majority of the users in our study were unable to tell what files they were sharing, and sometimes incorrectly assumed that they were not sharing any files when, in fact, they were sharing all files on their hard drive. An analysis of the KaZaA network suggested that a large number of users appeared to be unwittingly sharing personal and private files, and that some users were indeed taking advantage of this and downloading files containing ostensibly private information.

Introduction

The excitement about P2P systems has been encouraged by recent innovations that foster easier sharing of files, such as downloading simultaneously from multiple sources, and the sharing of many different file types, as well as improvements to the usability of these clients. Of the current P2P systems, KaZaA is by far the most popular and widely used, with more than 120 million downloads worldwide and an average of 3 million users online at any given time. The user interface ...