The rapidly advancing quantum computers challenge the cryptographic systems that are protecting today's digital infrastructure, including banking, healthcare, government services, and cloud platforms. As the new standardized post-quantum cryptographic (PQC) algorithms are slower and more complex than current cryptographic methods, the deployment of PQC algorithms become challenging. This project improves both the performance and security of the new PQC algorithms, enabling their wide adoption in real systems. The project's novelties include a unified approach that jointly optimizes speed and security across common computing platforms, and a systematic evaluation of hardware-level vulnerabilities that may arise during acceleration. The project's broader significance and importance are enabling a smooth and secure transition to quantum-resistant infrastructure, protecting critical data and services, and strengthening national cybersecurity readiness. The outcome of this project supports broader adoption of quantum-resistant cryptography, promote open-source dissemination of secure implementations, and contribute to workforce development for the quantum era. The project studies the standardized PQC algorithms, including hash-based, lattice-based, and code-based schemes, and optimize them across versatile platforms, including Central Processing Units (CPUs), Graphics Processing Units (GPUs), and embedded systems such as microcontrollers and Field-Programmable Gate Arrays (FPGAs). It applies parallel processing, instruction-level tuning, and hardware-software co-design to accelerate key operations such as hashing and polynomial transforms while preserving constant-time behavior. This project also analyzes timing, cache, power, and fault-based side-channels and develops defense mechanism such as masking, randomized scheduling, and redundant computation. The optimized implementations are integrated into practical systems, including secure network protocols, vehicular c