 This paper proposes a new method for creating backdoor attacks on EEG-based BCI systems using narrow period pulses. These pulses allow for the creation of backdoor keys that do not need to be synchronized with the EEG trials, making them easy to implement. The authors demonstrate the effectiveness and robustness of their approach, highlighting a serious security issue for EEG-based BCI systems. This article was authored by Lubin Meng, Xue Jiang, Jian Huang and others.