论文标题
通过渠道状态信息的无钥匙秘密通信
Keyless Covert Communication via Channel State Information
论文作者
论文摘要
当通道状态可在发射机或发射器和接收器中，在发射机和因果关系上，我们考虑通道状态在状态依赖性通道上的秘密通信问题。关于“看守”的对手的秘密沟通是，尽管通道上进行了交流，但看守的观察仍然与无辜的通道输入符号引起的输出无法区分。秘密沟通涉及欺骗对手，部分原因是代码手册的扩散；对于合法接收器的可靠解码，通常会通过看守无法提供的共享秘密密钥来删除代码簿的不确定性。与以前的工作相反，我们不假定发射器和合法接收器的共享密钥的可用性。取而代之的是，尽管渠道状态对看守者的产出影响，但从渠道状态中提取了共享的随机性，以使其对监狱长的秘密。当发射器和接收器处有通道状态时，我们会得出秘密容量区域。当通道状态仅在发射器上可用时，我们会在秘密容量上得出内部和外部边界。我们提供了秘密容量对渠道状态信息的知识为正面的示例，但没有信息为零。
We consider the problem of covert communication over a state-dependent channel when the channel state is available either non-causally, causally, or strictly causally, either at the transmitter alone or at both transmitter and receiver. Covert communication with respect to an adversary, called "warden," is one in which, despite communication over the channel, the warden's observation remains indistinguishable from an output induced by innocent channel-input symbols. Covert communication involves fooling an adversary in part by a proliferation of codebooks; for reliable decoding at the legitimate receiver, the codebook uncertainty is typically removed via a shared secret key that is unavailable to the warden. In contrast to previous work, we do not assume the availability of a shared key at the transmitter and legitimate receiver. Instead, shared randomness is extracted from the channel state in a manner that keeps it secret from the warden, despite the influence of the channel state on the warden's output. When channel state is available at the transmitter and receiver, we derive the covert capacity region. When channel state is only available at the transmitter, we derive inner and outer bounds on the covert capacity. We provide examples for which the covert capacity is positive with knowledge of channel state information but is zero without it.
