Abstract: We propose a CRC-NC(Cyclic Redundancy Check -Network Coding) scheme against pollution attack that exploit network coding and cyclic redundancy check code approach to detect the trustworthiness of the packets and decrease the probability of decoding error in the presence of pollution attack in the wireless two-way communication. In this paper, two nodes send packets to each other with the assistance of a relay node, and one node decoding packets which received from the other node and the relay. If S packets are correctly received from the other node directly, then K-S packets for which the Hamming weight are smallest are selected from all combination packets' Hamming weight for decoding. We show that the CRC-PNC scheme provides a significantly lower probability of decoding error than the random selection scheme and cryptographic schemes that require computational and bandwidth overheads．