A method and apparatus for providing a secure transmission based on a polar code are provided. A device generates an output bit sequence by applying a polar code generator matrix to an input bit sequence and transmits the output bit sequence to a target receiver. The input bit sequence includes first information bits, second information bits and third information bits. The first information bits correspond to gray bit channels for the target receiver and bad bit channels for an eavesdropper. The third information bits correspond to good bit channels for the target receiver and gray bit channels for the eavesdropper.