We address relay-assisted key generation wherein two wireless nodes, that have no direct channel between them, seek the assistance of an intermediate relay to generate secret keys. In a celebrated version of the relay-assisted protocol, as applied by Lai et al., Zhou et al., Wang et al. and Waqas et al., the relay node generates pair-wise keys with the two nodes, and then broadcasts an XOR version of the two keys. Although such protocols are simple and effective, we observe that they face reduction in key rates due to two problems. First, for confidentiality, the relay broadcasts an XOR function of the pair-wise keys thereby pruning the length of the shared key to be the minimum of the key lengths of the pair-wise keys. Secondly, the broadcast phase may also experience outages thereby not being able to share the generated key in every round of the protocol. Identifying these issues, we propose a buffer-aided relaying protocol wherein buffer is used at the relay to store unused secret bits generated in the previous rounds of the protocol so as to provide confidentiality in the subsequent rounds of broadcast. On this buffer-aided protocol, we propose a power-allocation strategy between the phases of key generation and broadcast so as to maximize the throughput and key rate. Rigorous analyses show that buffer-aided relay when implemented along with the proposed power-allocation strategy offer remarkable advantages over existing baselines.
翻译:我们处理的是中继辅助关键生成,即两个没有直接通道的无线节点,其中两个无线节点在它们之间没有直接通道,因此寻求中继中继中继器的协助以生成秘密钥匙。在莱等人、周等人、王等人和瓦卡斯等人应用的中继辅助协议的著名版本中,中继节点生成了双向钥匙,然后播放了两个节点的XOR版本。虽然这种协议简单而有效,但我们发现,由于两个问题,它们面临关键费率的降低。首先,为了保密,中继键播放配对键的 XOR 功能,从而将共享键的长度划为双向键关键长度的最小长度。第二,广播阶段也可能经历断电,从而无法将生成的钥匙与两个节点中的双向键共享,然后播放两个关键节点的 XOR 版本。我们提议一个缓冲辅助中继协议,在转发中继器中使用缓冲存储前几轮协议中生成的未使用的秘密部分。首先,以便在随后的几轮广播中继中继中继中继中继中继中继器提供保密性保密性,从而提供后一轮的保密。关于当前缓冲定位战略的缓冲定位,我们展示中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继中继战略,以展示战略。展示战略,我们。