A comprehensive survey of modern network security techniques and challenges

This review paper provides a comprehensive survey of modern network security techniques and the multifaceted challenges they address in an increasingly interconnected world. As cyber threats continue to evolve in both sophistication and frequency, organizations must deploy advanced defense mechanisms to protect sensitive data and maintain network integrity. We explore the shifting landscape of cyber threats, ranging from traditional attacks like malware and ransomware to more complex and persistent threats such as Advanced Persistent Threats (APTs) and zero-day exploits. The paper examines a range of defense strategies, including the implementation of Intrusion Detection and Prevention Systems (IDPS), which leverage both signature-based and anomaly-based detection techniques to identify malicious activities in real time. Additionally, we provide an in-depth analysis of modern encryption protocols like Transport Layer Security (TLS) and Virtual Private Networks (VPNs), which secure communication channels and protect data in transit. A significant portion of the paper is devoted to Zero-Trust Architecture (ZTA), a security model that eliminates implicit trust within a network and enforces strict verification for every access request. We discuss the principles of zero trust, its growing adoption, and the associated implementation challenges in large-scale environments. Moreover, the paper delves into the integration of Machine Learning (ML) and Artificial Intelligence (AI) in cyber security, exploring their role in threat detection, automated response systems, and the enhancement of threat intelligence. We also address the unique security challenges posed by emerging technologies such as the Internet of Things (IoT) and cloud computing, which introduce new vulnerabilities due to device heterogeneity, scalability issues, and shared responsibility models. This review outlines the current state of network security technologies, highlights key challenges in securing modern networks, and explores future trends such as quantum-resistant encryption and AI-driven automation in cybersecurity.'