Lightweight block ciphers are critical for ensuring secure data transmission in resource-limited Internet of Things (IoT) devices. In designing secure and efficient lightweight block ciphers, balancing diffusion property and resource consumption becomes a key metric. This paper proposes QLW, a highly diffusive lightweight block cipher, designed to meet the growing security needs of resource-constrained devices. QLW employs a combined variant form of generalized Feistel structure (GFS) and Lai-Massey structure as its underlying structure. The QLW round function adopts a GFS, refined into a doub...