Covert communications on Poisson packet channels
Covert communications on Poisson packet channels
复制标题
泊松数据包通道上的隐蔽通信
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Amir Houmansadr
中科院分区：
文献类型：
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作者：
Ramin Soltani;D. Goeckel;D. Towsley;Amir Houmansadr
考虑一个信道，其中授权发送器Jack根据泊松过程以每秒λ个分组的速率在时间段T内向授权接收器Steve发送分组。假设秘密发送者Alice希望在同一信道上向秘密接收者Bob传递信息，而不被警惕的对手Willie发现。我们考虑两种情况。在第一种情况下，我们假设管理员威利不能查看数据包内容，只能观察数据包的时间，而爱丽丝必须通过将自己的数据包插入通道来发送信息。我们表明，数据包的数量，爱丽丝可以偷偷地发送给鲍勃的顺序是数据包的数量，杰克发送给史蒂夫的平方根;相反，如果爱丽丝发送超过，她将被威利检测到的概率很高。在第二种情况下，我们假设威利可以查看数据包内容，但爱丽丝可以通过改变从杰克到史蒂夫的数据包的时间来通过M/M/1队列与鲍勃进行通信。首先，Alice构建码本，每个码字由用于传送与该码字相关联的信息的分组定时序列组成。然而，为了成功地使用该码本，Alice必须总是在适当的时间发送分组。因此，利用我们的结果从第一种情况下，我们提出了一个建设，其中爱丽丝隐蔽地减慢数据包流，以便缓冲数据包使用在随后的码字传输阶段。利用该方法，在服务率μ > e · λ的M/M/1队列上，Alice可以在时间T内隐蔽可靠地向Bob发送O（λT）个隐蔽比特.
Consider a channel where authorized transmitter Jack sends packets to authorized receiver Steve according to a Poisson process with rate λ packets per second for a time period T. Suppose that covert transmitter Alice wishes to communicate information to covert receiver Bob on the same channel without being detected by a watchful adversary Willie. We consider two scenarios. In the first scenario, we assume that warden Willie cannot look at packet contents but rather can only observe packet timings, and Alice must send information by inserting her own packets into the channel. We show that the number of packets that Alice can covertly transmit to Bob is on the order of the square root of the number of packets that Jack transmits to Steve; conversely, if Alice transmits more than that, she will be detected by Willie with high probability. In the second scenario, we assume that Willie can look at packet contents but that Alice can communicate across an M/M/1 queue to Bob by altering the timings of the packets going from Jack to Steve. First, Alice builds a codebook, with each codeword consisting of a sequence of packet timings to be employed for conveying the information associated with that codeword. However, to successfully employ this codebook, Alice must always have a packet to send at the appropriate time. Hence, leveraging our result from the first scenario, we propose a construction where Alice covertly slows down the packet stream so as to buffer packets to use during a succeeding codeword transmission phase. Using this approach, Alice can covertly and reliably transmit O(λT) covert bits to Bob in time period T over an M/M/1 queue with service rate μ > e · λ.