Untraceable dynamic-identity-based remote user authentication scheme with verifiable password update

People are always concerned about privacy. Techniques tracing specific user activities may damage privacy seriously. To protect user privacy, a dynamic-identity-based remote user authentication scheme will be proposed in this manuscript. This scheme employs smart cards to achieve mutual authentication, and no verifier table is needed. Via this scheme, transmitted identities are always fresh such that untraceability is ensured, and a user can change his or her password after being authenticated successfully. Copyright (c) 2013 John Wiley & Sons, Ltd.