This Special Issue of the journal Sensors will focus on “Network security and IoT Security”, with a broad focus on the following (but not exhaustive) list of topics: - IoT security threats and mitigation - Access management - Improved authentication - Wireless security - Firewalls and honeypots - Endpoint security - Digital piracy - Biometrics in security - Malware detection - Information security - Cloud security - Ransomware - Risk management - Digital forensics - Challenges in remote访问 - 数据存储安全性 - 数据丢失预防系统 - 社交媒体安全 - 密码学 - 区块链 - 移动应用程序安全