Scope SecureComm is a conference in EAI core conference portfolio focusing on cybersecurity. The aim of SecureComm is to bring together researchers and practitioners in academic, industry, and government in security, networking, communication and other related communities to explore important research directions in the field. The 21st SecureComm conference seeks submissions of high-quality research contributions. Topics of interest encompass all areas of secure communications and networking. Topics in less related areas will be considered if a clear connection to secure communication and networking is demonstrated. Topics addressing interdisciplinary challenges in different application domains are welcome. Topics Security and privacy in computer networks (e.g., wired, wireless, mobile, hybrid, sensor, vehicular, satellite, 5G, 6G, ad hoc, peer-to-peer, and software-defined networks) Security and privacy in systems with strong secure communication and networking element (e.g., security in the cloud, IoT, cyber-physical systems, edge and fog computing, and teleconferencing) Security and privacy in Web3.0 and metaverse Distributed ledger technologies (e.g., blockchain, smart contracts, and cryptocurrencies) and decentralized applications (e.g., DeFi) Security protocols at all network layers and for different applications (e.g., for secure routing, naming/addressing, network management, remote authentication and attestation) Physical layer security (e.g., jamming, GPS spoofing) Network attacks and forensics (e.g., DDoS, MitM, malware, botnets, side-channel attacks, phishing/pharming, cybersquatting), defenses (e.g., network intrusion detection and prevention, firewalls, packet filters, moving target defence) Applications of cryptography (e.g., Analysis of deployed cryptography and cryptographic protocols, Cryptographic implementation analysis, New cryptographic protocols with real-world applications) Security analysis (e.g., Malware analysis, Automated security analysis of source code and binaries, Program analysis) Data-driven security and measurement studies (e.g., Measurements of fraud, malware or spam; Measurements of human behavior and security) Cybercrime investigation and attribution Cyber threat intelligence and cyber incident responses Anonymous and privacy-aware communications (e.g., Tor, darknet) Internet censorship and circumvention Secure communication and networking applications (e.g., industry 4.0, energy, transportation, smart cities) Quantum key distribution and other quantum-based secure communications Visualization of secure communications and networking Privacy-preserving computing in secure communication and networking (e.g., privacy-preserving machine learning) The resilience of computer networks and critical infrastructures Web and mobile security and privacy Defending false information online (e.g., mis-, dis- and mal-information) Socio-technical aspects of secure communications and networking (e.g., usability, human behaviors, legal issues, cybercrime, economics) Security and privacy of contact tracing and other COVID-19 related digital interventions with a core element on telecommunications or networking