Techniques are disclosed for authentication and identification of a user by use of an electroencephalographic (EEG) signal. For example, a method for authenticating a user includes the following steps. At least one electroencephalographic response is obtained from a user in accordance with perceptory stimuli presented to the user. The user is authenticated based on the obtained electroencephalographic response. The authenticating step may be based on detection of an event-related potential in the obtained electroencephalographic response. The event-related potential may be a P300 event-related potential. The method may also include the step of enrolling the user prior to authenticating the user. The enrolling step may include a supervised enrollment procedure or an unsupervised enrollment procedure.