This paper considers the covert identification problem in which a sender aims to reliably convey an identification (ID) message to a set of receivers via a binary-input discrete memoryless channel (BDMC), and simultaneously to guarantee that the communication is covert with respect to a warden who monitors the communication via another independent BDMC. We prove a square-root law for the covert identification problem. This states that an ID message of size \exp(\exp(\Theta(\sqrt{n}))) can be transmitted over n channel uses. We then characterize the exact pre-constant in the \Theta(.) notation. This constant is referred to as the covert identification capacity. We show that it equals the recently developed covert capacity in the standard covert communication problem, and somewhat surprisingly, the covert identification capacity can be achieved without any shared key between the sender and receivers. The achievability proof relies on a random coding argument with pulse-position modulation (PPM), coupled with a second stage which performs code refinements. The converse proof relies on an expurgation argument as well as results for channel resolvability with stringent input constraints.
翻译:本文考虑了一个发件人试图通过二进制离散内存性无内存性信道(BDMC)向一组接收器可靠传递识别(ID)信息的秘密识别问题,同时保证该通信对于通过另一个独立的BDMC监测通信的监管员来说是隐蔽的。 我们证明这是一个隐蔽识别问题的平地法律。 这表明大小为\ exp( theta( Theta( sqrt{n}))) 的识别信息可以通过 n 频道的用途传输。 然后我们在\ Theta(.) 标记中描述准确的预封前状态。 这个常态被称为隐蔽识别能力。 我们显示它相当于最近在标准隐蔽通信问题中开发的隐蔽能力, 有点令人惊讶的是, 隐蔽识别能力可以在发送者和接收者之间不使用任何共享的密钥的情况下实现。 递解证据依赖于带有脉冲定位调控调( PPM) 的随机编译参数, 以及进行代码改进的第二个阶段。 反证依据严格性约束性参数, 和严格性导线的参数, 以及再导结果。