How Unique and Traceable Are Usernames?

Abstract

International audienceSuppose you find the same username on different online services, what is the probability that these usernames refer to the same physical person? This work addresses what appears to be a fairly simple question, which has many implications for anonymity and privacy on the Internet. One possible way of estimating this probability would be to look at the public information associated to the two accounts and try to match them. However, for most services, these information are chosen by the users themselves and are often very heterogeneous, possibly false and difficult to collect. Furthermore, several websites do not disclose any additional public information about users apart from their usernames (e.g., discus- sion forums or Blog comments), nonetheless, they might contain sensitive information about users. This paper explores the possibility of linking users profiles only by looking at their usernames. The intuition is that the probability that two usernames refer to the same physical person strongly depends on the "entropy" of the username string itself. Our experiments, based on crawls of real web services, show that a significant portion of the users' profiles can be linked using their usernames. To the best of our knowledge, this is the first time that usernames are considered as a source of information when profiling users on the Internet

Exploring Touch-Screen Biometrics for User Identification on Smart Phones

“…Regarding issues to users' anonymity, a recent study has demonstrated that pseudonyms chosen by users at different websites can be linked to deduce their real identity [28]. This probability of linking and profiling users could increase if users' pseudonyms can be identified based on their lock pattern behavior when authenticating into different services.…”

A Closer Look at Third-Party OSN Applications: Are They Leaking Your Personal Information?

“…Moreover, as the user ID is unique, it can be used to track a user across different apps. Finally, there is substantial evidence that user ID (and username) can be used to (re)identify a user [8]. We observe that 1% of apps are transmitting age to an external entity; this attribute is considered highly sensitive and only few users disclose it publicly [3].…”

Online Social Network Profile Linkage

“…Zafarani et al [20] explored how the behavior features of how users express themselves and generate their usernames. Perito et al [16] studied username choice discloses our identities to public, while Liu et al [12] improves name disambiguation by modeling the commonality of usernames, to help better estimate the linkage likelihood.…”