Encryption scheme of physical layer based on irregular LDPC codes

In order to improve the security level of the physical layer, a new encryption scheme based on the irregular low-density parity-check (LDPC) codes is proposed in this paper. The degree distribution property of the irregular LDPC codes and a large random number are applied to encrypt the plaintext. Analyses show that the proposed scheme can provide an acceptable security level for the communication systems. The secret key size of this scheme is much smaller than those of the previous symmetric-key McEliece-like schemes. Moreover, there is no trade-off between the error correction performance and the security level in the proposed scheme.