This book presents the proceedings of the Fifth International Conference on Safety and Security with IoT (SaSeIoT 2021), which took place online. The conference aims to explore not only IoT and its related critical applications but also IoT towards Security and Safety. The conference solicits original and inspiring research contributions from experts, researchers, designers, and practitioners in academia, industry and related fields and provides a common platform to share knowledge, experience and best practices in various domains of IoT.

1. Opportunistic Multi-Modal User Authentication for Health-Tracking IoT Wearables.- 2. On-Phone CNN Model-based Implicit Authentication to Secure IoT Wearables.- 3. A Cybersecurity Guide for Using Fitness Devices.- 4. An efficient algorithm for human abnormal behaviour detection using object detection and pose estimation.- 5. A Secure and Scalable IoT Consensus Protocol.- 6. Session Key Agreement Protocol for Secure D2D Communication.- 7. What Do Your Smart-Home Devices Reveal About You?.- 8. A Quantum-Resistant and Fast Secure Boot for IoT Devices Using Hash-Based Signatures and SRAM PUFs.- 9. On the Analysis of MUD-Files' Interactions, Conflicts, and Configuration Requirements Before Deployment.- 10. Natural Scenes' Text Detection and Recognition using CNN and Pytesseract.- 11. Assessing the Resistance of Internet of Things Applications Against Memory Corruption Attacks: A Case Study for Contiki and Tizen.- 12. IoT geography chain: Blockchain based solution for Logistics eco system.