Unobservable Re-authentication for Smartphones

The widespread usage of smartphones gives rise to new security and privacy concerns. Smartphones are becoming a personal entrance to networks, and may store private information. Due to its small size, a smartphone could be easily taken away and used by an attacker. Using a victim’s smartphone, the attacker can launch an impersonation attack, which threatens the security of current networks, especially online social networks. Therefore, it is necessary to design a mechanism for smartphones to re-authenticate the current user’s identity and alert the owner when necessary. Such a mechanism can help to inhibit smartphone theft and safeguard the information stored in smartphones. In this paper, we propose a novel biometric-based system to achieve continuous and unobservable re-authentication for smartphones. The system uses a classifier to learn the owner’s finger movement patterns and checks the current user’s finger movement patterns against the owner’s. The system continuously re-authenticates the current user without interrupting user-smartphone interactions. Experiments show that our system is efficient on smartphones and achieves high accuracy.