Methods, systems, and devices for wireless communications are described. In some examples, a wireless device may modify a cyclic redundancy check (CRC) generation and attachment operation based on a secret key to support enhanced security. In some examples, a first device may identify a set of data to transmit to a second device and prior to transmitting the set of data, the first device and the second device may obtain a set of key bits for data protection. The first device may generate a bit vector based on a subset of the set of key bits and a cyclic redundancy check polynomial. The transmitting device may then generate an encoded codeword based on the bit vector and transmit the encoded codeword to the second wireless device. The second device may decode the encoded codeword and obtain the set of data based on the set of key bits.