  The Telecare medicine information system (TMIS) is developed to provide
Telecare services to the remote user. A user can access remote medical servers
using internet without moving from his place. Although remote user and server
exchange their messages/data via public networks. An adversary is considered to
be enough powerful that he may have full control over the public network. This
makes these Telecare services vulnerable to attacks. To ensure secure
communication between the user and server many password based authentication
schemes have been proposed. In 2013, Hao et al. presented chaotic maps-based
password authentication scheme for TMIS. Recently, Lee identified that Hao et
al.'s scheme fails to satisfy key agreement property, such that a malicious
server can predetermine the session key. Lee also presented an efficient
chaotic map-based password authentication and key agreement scheme using Smart
cards for TMIS. In this article, we briefly review Lee's scheme and
demonstrates the weakness of Lee's scheme. The study shows that the Lee's
scheme inefficiency of password change phase causes denial of service attack
and login phase results extra computation and communication overhead.
