QuanCrypt-FL introduces a secure and efficient federated learning framework that combines fully homomorphic encryption, low-bit quantization, dynamic pruning, and mean-based clipping to defend against gradient inversion and membership inference attacks. The proposed approach significantly reduces communication and computational overhead while maintaining model accuracy. Extensive evaluations on MNIST, HAM10000, CIFAR-10, and CIFAR-100 demonstrate substantial improvements in efficiency, including up to 9× faster encryption, 16× faster decryption, 3× faster training, and 1.5× faster inference compared with existing secure federated learning methods.