We study the two-transmitter two-receiver channel with confidential messages channel under a secrecy constraint, exploring the effect of a single eavesdropper on the secure communication rate. A general achievable secrecy rate region and an outer bound are derived for the degraded version of this channel. An example is provided in which the inner and outer bound meet. For the general non-degraded channel, another outer bound is derived and a special case is highlighted in which the inner and outer bound meet. Our inner bound recovers the known inner bounds for the multiple-access wiretap channel, broadcast channel with confidential messages, and the compound MAC channel.
We study the two-transmitter two-receiver channel with confidential messages channel under a secrecy constraint, exploring the effect of a single eavesdropper on the secure communication rate. A general achievable secrecy rate region and an outer bound are derived for the degraded version of this channel. An example is provided in which the inner and outer bound meet. For the general non-degraded channel, another outer bound is derived and a special case is highlighted in which the inner and outer bound meet. Our inner bound recovers the known inner bounds for the multiple-access wiretap channel, broadcast channel with confidential messages, and the compound MAC channel.
Motivated in part by the problem of secure multicast distributed storage, we analyze secrecy rates for a channel in which two transmitters simultaneously multicast to two receivers in the presence of an eavesdropper. Achievable rates are calculated via extensions of a technique due to Chia and El Gamal and the method of output statistics of random binning. Outer bounds are derived for both the degraded and non-degraded versions of the channel, and examples are provided in which the inner and outer bounds meet. The inner bounds recover known results for the multiple-access wiretap channel, broadcast channel with confidential messages, and the compound MAC channel. An auxiliary result is also produced that derives an inner bound on the minimal randomness necessary to achieve secrecy in multiple-access wiretap channels.
Motivated in part by the problem of secure multicast distributed storage, we analyze secrecy rates for a channel in which two transmitters simultaneously multicast to two receivers in the presence of an eavesdropper. Achievable rates are calculated via extensions of a technique due to Chia and El~Gamal and also the method of output statistics of random binning. An intriguing synergy is observed between the achievable rate expressions arising from the two techniques: the rate region of the latter is simplified via a constraint that is discovered while deriving the former rate region. Outer bounds are derived for both the degraded and non-degraded versions of the channel, and examples are provided in which the inner and outer bounds meet. The inner bounds recover known results for the multiple-access wiretap channel, broadcast channel with confidential messages, and the compound MAC channel. An auxiliary result is also produced that characterizes the minimal randomness necessary to achieve secrecy in multiple-access wiretap channels.
In this paper, we study the problem of secret communication over a Multiple Access Wire-tap Channel with Common Message. Here, we assume that two transmitters have confidential messages which must be kept secret from the eavesdropper (the second receiver), and both of them have access to a common message which can be decoded by two receivers. For this setting, we derive general inner and outer bounds on the secrecy capacity region for the discrete memoryless case as well as for Gaussian one. Providing numerical examples for the Gaussian case, we illustrate the comparison between derived achievable rate regions and outer bounds for our considered model and the capacity region of compound multiple access channel.
In this paper, we study the problem of secret communication over a Multiple Access Wire-tap Channel with Common Message. In this channel, we assume that two transmitters have confidential messages which must be kept secret from the eavesdropper (receiver 2), and both of them have a common message which can be decoded by two receivers. For this setting, in the discrete memoryless case we derive general inner and outer bounds on the secrecy capacity region. Also, we derive inner and outer bounds on the secrecy capacity region for the Gaussian case. Providing numerical examples for the Gaussian case, we illustrate the comparison between derived achievable rate regions, outer bounds and the capacity region of compound multiple access channel.
We study the multi-receiver wiretap channel with public and confidential messages. In this channel, there is a transmitter that wishes to communicate with two legitimate users in the presence of an external eavesdropper. The transmitter sends a pair of public and confidential messages to each legitimate user. While there are no secrecy constraints on the public messages, confidential messages need to be transmitted in perfect secrecy. We study the discrete memoryless multi-receiver wiretap channel as well as its Gaussian multi-input multi-output (MIMO) instance. First, we consider the degraded discrete memoryless channel, and obtain an inner bound for the capacity region by using an achievable scheme that uses superposition coding and binning. Next, we obtain an outer bound, and show that this outer bound partially matches the inner bound, providing a partial characterization for the capacity region of the degraded channel model. Second, we obtain an inner bound for the general, not necessarily degraded, discrete memoryless channel by using Marton's inner bound, superposition coding, rate-splitting and binning. Third, we consider the degraded Gaussian MIMO channel, and show that, to evaluate both the inner and outer bounds, considering only jointly Gaussian auxiliary random variables and channel input is sufficient. Since the inner and outer bounds partially match, these sufficiency results provide a partial characterization of the capacity region of the degraded Gaussian MIMO channel. Finally, we provide an inner bound for the capacity region of the general, not necessarily degraded, Gaussian MIMO multi-receiver wiretap channel.
In this paper, we study the problem of secret communication over a Compound Multiple Access Channel (MAC). In this channel, we assume that one of the transmitted messages is confidential that is only decoded by its corresponding receiver and kept secret from the other receiver. For this proposed setting (compound MAC with confidential messages), we derive general inner and outer bounds on the secrecy capacity region. Also, as examples, we investigate `Less noisy' and `Gaussian' versions of this channel, and extend the results of the discrete memoryless version to these cases. Moreover, providing numerical examples for the Gaussian case, we illustrate the comparison between achievable rate regions of compound MAC and compound MAC with confidential messages.