The advent of Industry 4.0 has led to the transformation of traditionalmanufacturing into smart factories. However, this shift has also exposedfactories to new security risks, including information leakage and unauthorizedaccess to sensitive data. To address these concerns, this chapter proposes anovel approach that integrates Internet of Things (IoT) technology withblockchain to create a secure and reliable authentication system. Thislightweight password security solution offers several benefits, including dataprotection, low management costs, and enhanced security.Furthermore, this research highlights the importance of addressing emergingsecurity threats, such as man-in-the-middle attacks, replay attacks, and serverspoofing attacks, to ensure the integrity and confidentiality of industrialdata in smart factories.