Improved on an efficient user authentication scheme for heterogeneous wireless sensor network tailored for the Internet of Things environment

Recently, Farasha et al. proposed an efficient user authentication and key agreement scheme for heterogeneous wireless sensor network tailored for the Internet of Things environment. By using BAN-logic and AVISPA tools, they confirm the security properties of the proposed scheme. However, after analyzing, we determine that the scheme could not resist the smart card loss password guessing attack, which is one of the ten basic requirements in a secure identity authentication using smart card, assisted by Liao et al. Therefore, we modify the method to include the desired security functionality, which is significantly important in a user authentication system using smart card.