Key exchange mechanisms are foundational to secure communication, yet traditional methods face challenges from quantum computing. The Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM) is a post-quantum cryptographic key exchange protocol with unknown successful quantum vulnerabilities. This study evaluates the ML-KEM using experimental benchmarks. We implement the ML-KEM in Python for clarity and in C++ for performance, demonstrating the latter’s substantial performance improvements. The C++ implementation achieves microsecond-level execution times for key generation, encapsulation, and decapsulation. Python, while slower, provides a user-friendly introduction to the ML-KEM’s operation. Moreover, our Python benchmark confirmed that the ML-KEM consistently outperformed RSA in execution speed across all tested parameters. Beyond benchmarking, the ML-KEM is shown to handle the computational hardness of the Module Learning With Errors (MLWE) problem, ensuring resilience against quantum attacks, classical attacks, and Artificial Intelligence (AI)-based attacks, since the ML-KEM has no pattern that could be detected. To evaluate its practical feasibility on constrained devices, we also tested the C++ implementation on a Raspberry Pi 4B, representing IoT use cases. Additionally, we attempted to run integration and benchmark tests for the ML-KEM on microcontrollers such as the ESP32 DevKit, ESP32 Super Mini, ESP8266, and Raspberry Pi Pico, but these trials were unsuccessful due to memory constraints. The results showed that while the ML-KEM can operate effectively in such environments, only devices with sufficient resources and runtimes can support its computational demands. While resource-intensive, the ML-KEM offers scalable security across diverse domains such as IoT, cloud environments, and financial systems, making it a key solution for future cryptographic standards.

SYN flooding attacks remain a persistent threat to network availability, particularly in Distributed Denial-of-Service (DDoS) scenarios that exploit the TCP three-way handshake. Traditional SYN cookies mitigate half-open connection exhaustion but may exhibit limited replay resistance under certain adversarial conditions. This paper presents a nonce-enhanced, HMAC-SHA256-based SYN cookie mechanism designed to strengthen handshake validation while preserving stateless operation. The implemented framework binds each connection attempt to a time-bounded, per-session nonce and embeds a truncated HMAC within the TCP sequence number field. The mechanism is implemented and experimentally evaluated using a custom-built simulation framework, NOxSYN. Under concurrent SYN flood conditions, the enhanced design successfully validated legitimate handshakes while maintaining stable operation under adversarial load. Measured server-side cryptographic processing remained below 1 ms per connection, with stable CPU utilization during testing. These results demonstrate that nonce-based replay protection can be integrated into a SYN cookie framework while preserving scalability and stateless operation. The current evaluation focuses on implementation-level validation and performance characterization, providing a foundation for future security-oriented assessment across a broader range of replay-based attack scenarios.