This volume constitutes selected papers presented at the First Inernational Conference on Ubiquitous Security, UbiSec 2021, held in Guangzhou, China, in December 2021.The presented 26 full papers and 2 short papers were thoroughly reviewed and selected from the 96 submissions.

 A Backdoor Embedding Method for Backdoor Detection in Deep Neural Networks.- Security and Privacy for Sharing Electronic Medical Records Based on Blockchain and Federated Learning.- A Fine-grained Access Control Scheme for Electronic Health Records Based on Roles and Attributes.- Active Malicious Accounts Detection with Multimodal Fusion Machine Learning Algorithm.- Evaluation of an Anomaly Detector for Routers using Parameterizable Malware in an IoT Ecosystem.- PUFloc: PUF and Location Based Hierarchical Mutual Authentication Protocol for Surveillance Drone Networks.- Smart Search over Encrypted Educational Resources in Cloud Storage.- SDGen: A Scalable, Reproducible and Flexible Approach to Generate Real World Cyber Security Datasets.- Towards a Location-Aware Blockchain-Based Solution to Distinguish Fake News in Social Media.- Using Streaming Data Algorithm for Intrusion Detection on the Vehicular Controller Area Network.- Privacy-Enhanced Mean-Variance Scheme Against Malicious Signature Attacks in Smart Grids Privacy-preserving Cluster Validity.- A Large-Scale Study on the Security Vulnerabilities of Cloud Deployments Design & Architecture of Progger 3: A Low-Overhead, Tamper-Proof Provenance System.- Skill Reward for Safe Deep Reinforcement Learning.- Generalizing Supervised Learning for Intrusion Detection in IoT Mesh Networks.- Reliable and Controllable Data Sharing Based on Blockchain,. A Network Forensics Investigating Method Based on Weak Consistency for Distributed SDN.- Intrusion Detection System Based on Deep Neural Network and Incremental Learning for In-Vehicle CAN Networks.- Towards a Two-tier Architecture for Privacy-enabled Recommender Systems (PeRS).- A Supervised Rare Anomaly Detection Technique via Cooperative Co-Evolution-Based Feature Selection using Benchmark UNSW_NB15 Dataset.- Towards Evaluating the Effectiveness of Botnet Detection Techniques.- A Robust Malware Detection Approach for Android System based on Ensemble Learning.- A Reverse Auction Based Efficient D2D Transmission Mechanism for Ubiquitous Power Terminals.- A Fine-tuning Strategy Based on Real Scenes in Gait Identification An Online Automated Anti-Anti-Virus Method.- Research on Bandwidth Reservation Algorithm of Teaching Resources in Cloud Computing Environment.- An Edge-Cloud Collaborative Object Detection System.