A Virtual Password Scheme to Protect Passwords

In this paper, we discuss how to prevent users´ passwords from being stolen by adversaries. We propose a virtual password concept involving a small amount of human computing to secure users´ passwords in on-line environments. We adopt user-determined randomized linear generation functions to secure users´ passwords based on the fact that a server has more information than any adversary does. We analyze how the proposed scheme defends against phishing, key logger, and shoulder-surfing attacks.