In this brief, a high-speed secret merchant-4 (SM4) cryptographic circuit with strong robustness against differential power analysis (DPA) attacks is proposed for securing the wireless networks for the first time. To achieve a high-throughput design for the SM4 algorithm, 32-stage pipelined encryption rounds and key expansion rounds are employed. Moreover, to resist DPA attacks, one pseudorandom number generator (PRNG) is embedded to randomly alter the SM4 circuit with a 32-stage or 34-stage pipeline, the other PRNG is utilized for realizing redundant operations to further break the correlation between the processed data and power dissipation of the SM4 circuit. When compared to a regular SM4 cryptographic circuit, the proposed SM4 architecture is capable of achieving a high throughput and satisfactory robustness against DPA attacks without compromising much power, area, and performance overhead. The result shows that the pipelined SM4 cryptographic circuit achieves a 128-Gbps throughput and 47423- $\mu \text{m}^{2}$ area with a high measurement-to-disclosure (MTD) value (>1 million) after synthesizing in the SMIC 14-nm process design kits (PDKs).