ABSTRACT The evolution of connected and autonomous vehicles (CAVs) and software‐defined vehicles (SDVs) accelerates the transition of in‐vehicle networks to automotive Ethernet (AE)‐centric zonal architectures to satisfy higher bandwidth and scalability requirements. However, this transition introduces increasing security challenges in automotive electronic control units (ECUs). In particular, as the medium for live video streaming migrates from point‐to‐point low‐voltage differential signaling (LVDS) to switched AE, secure video transmission becomes significant for ECUs with limited CPU resources. Existing SRTP/AES configurations are not tailored to raw‐format live video over AE and can exceed CPU budgets, motivating a lightweight, implementation‐ready solution. Therefore, this research proposes a lightweight encryption scheme for raw‐format live video streaming over AE, implemented by integrating a reduced‐round AES‐ICM into a GStreamer/libsrtp pipeline. The evaluation on a testbed demonstrates that the proposed scheme outperforms a conventional encryption scheme in terms of CPU overhead, throughput, latency, and frame rate, offering practical guidance for CPU‐constrained ECUs in AE‐centric architectures.