The utilization of smart cards for authentication has become increasingly prevalent in today's digital landscape, primarily due to their convenience and ability to streamline access to secure systems. These compact devices not only serve as physical tokens for identity verification but also store sensitive information that can facilitate secure transactions and interactions. Despite these advantages, the reliance on smart cards also introduces considerable security challenges, particularly in scenarios where a card is lost or stolen. In this paper, we delve deeply into the vulnerabilities associated with lost smart cards, focusing particularly on the attack methodology proposed by Juang et al. Their scheme outlines a password-authenticated key agreement protocol designed to enhance security. However, our analysis reveals several critical weaknesses within this framework that could be exploited by malicious actors. As we explore these vulnerabilities, we also present targeted recommendations for bolstering the security of smart card authentication systems. Our objective is to enhance the overall resilience of these systems, ensuring that they not only provide the convenience users desire but also safeguard against the threats posed by lost cards.
Key Exchange, Elliptic Curve Cryptosystem, Smart Card, Authentication