Methods, systems, and devices for wireless communications are described. In a multilevel encoding scheme, a transmitting device may divide a stream of information bits in a message into multiple substreams, and the transmitting device may input each substream to a different level of an encoder such that each substream is encoded separately. The transmitting device may also input excess bits to some levels of the encoder to add physical layer security to the message. To improve the chances that a receiving device is able to correctly decode the message, the receiving device may be configured to identify the levels at which the excess bits are encoded. Accordingly, the receiving device may be able to decode the information bits in the message and avoid attempting to decode the excess bits in the message as information bits.