基于侧边协作系统的物理层密钥生成方案

传统侧边协作系统下用于生成密钥的信道特征值是协作信道与直接信道的乘积，这种方案的密钥生成速率较低。为提高密钥生成速率，提出利用两个独立信道的信道特征之和来生成密钥。在前两个时隙，合法通信双方通过信道探测，获得其直接信道的信道状态信息。在后两个时隙，合法双方分别获得各自与协作信道之间的信道状态信息。最后利用直接信道与协作信道的和作为随机密钥源。基于侧边协作系统，分两种情况介绍该方案：单个侧边协作节点，单个双向协作节点。仿真结果表明，该方案可以获得更高的密钥生成速率，并且随着SNR的增加，该方案泄露的信息量趋向于一个常数。

Physical-layer Secret Key Generation Scheme based on Side Cooperative Systems

Traditional secret key generation scheme in side cooperative system uses the product of cooperative channel and direct channel to generate secret keys, which reduces the key generation rate. To solve this problem, this paper proposes a new scheme which uses the sum of two independent channels state information to generate secret keys. The first two slots are exploited to build a pairwise observation of the direct channel by channel detection. And in the last two slots, the legitimate users build a pairwise observation of the cooperative channel respectively. At last, the sum of the direct channel and cooperative channel are used to generate secret keys. The scheme can be divided into two scenarios: side cooperative node, two-way cooperative node. Simulation results show that the proposed scheme can achieve a higher secret key rate. Furthermore, the rate of channel information that leaks is also calculated which tends to be constant as SNR increases.