International Journal of Reconfigurable and Embedded Systems (IJRES) Vol. 13, No. 3, November 2024, pp. 586~594 ISSN: 2089-4864, DOI: 10.11591/ijres.v13.i3.pp586-594  586 Journal homepage: http://ijres.iaescore.com Robust embedded access control system based on face and encrypted QR with RPi4 Samir Marwan Hammami 1 , Muhammad Alhammami 2 1 Department of Management Information Systems, Dhofar University, Salalah, Oman 2 Department of Communication, Higher Institute for Applied Sciences and Technology, Damascus, Syria Article Info ABSTRACT Article history: Received Jan 26, 2024 Revised May 3, 2024 Accepted May 17, 2024 Facial-based recognition systems are commonly used for building access control, with the accuracy and computing requirements still being improved. On the other hand, QR codes are gaining rising attention as an input interface to many embedded applications. This paper proposes an embedded access control system that customises both previous techniques to be implemented on the CPU of a low-cost Raspberry Pi 4 computer. The achieved system works smoothly with a frame rate of 8.27 FPS, increasing the accessing control's robustness compared to a system based on face recognition only. It also offers the ability to control the access of unknown faces. In tandem with integration, this strengthens security measures, improves user experience, and outperforms conventional access control approaches, creating an attractive offer for many businesses. Keywords: Access control Deep metric learning Face recognition QR codes Raspberry Pi 4 This is an open access article under the CC BY-SA license. Corresponding Author: Muhammad Alhammami Department of Communication, Higher Institute for Applied Sciences and Technology P.O. Box 31983, Damascus, Syria Email: Muhammad.Alhammami@hiast.edu.sy 1. INTRODUCTION One of the most important aspects of building security is access control. Conventional systems generally depend on passwords, keys, or cards that can be misplaced, stolen, or forgotten. Facial recognition technologies have been employed more lately and provide a more user-friendly and secure option. Nonetheless, there are still issues with these systems' accuracy and processing demands. Moreover, they are unable to restrict access for unidentified faces. Numerous researches have looked on the application of face recognition to access control. These efforts have helped to lower the processing requirements and increase the accuracy of facial recognition systems. They do not, however, address the problem of limiting access for unknown persons and instead concentrate mostly on well-known faces. However, there may be a workaround for this issue as QR codes have been employed as an input interface for a number of embedded programs. A detachable color two- dimensional code design is presented [1] in which the authors presented a state-of-the-art technique for producing two-dimensional codes with distinct color components. Information on the potential benefits and applications of this design is provided by the research. Research by Yang et al. [2] introduces a two-dimensional code hierarchical encryption algorithm based on attribute encryption. The authors propose attribute-based encryption as an encryption method to increase the security of two-dimensional codes. The study emphasizes the advantages of using this hierarchical encryption method to protect sensitive information. A logistic information privacy protection system based on encrypted QR code is described [3]. They provide a method that protects the confidentiality