In this paper, inner and outer bounds on the capacity region of two-user interference channels with two confidential messages have been proposed. By adding secure multiplex coding to the error correction method in [15] which achieves the best achievable capacity region for interference channel up to now, we have shown that the improved secure capacity region compared with [2] now is the whole Han-Kobayashi region. In addition, this construction not only removes the rate loss incurred by adding dummy messages to achieve security, but also change the original weak security condition in [2] to strong security. Then the equivocation rate for a collection of secret messages has also been evaluated, when the length of the message is finite or the information rate is high, our result provides a good approximation for bounding the worst case equivocation rate. Our results can be readily extended to the Gaussian interference channel with little efforts.
In this paper, inner and outer bounds on the capacity region of two-user interference channels with two confidential messages have been proposed. By adding secure multiplex coding to the error correction method in [15] which achieves the best achievable capacity region for interference channel up to now, we have shown that the improved secure capacity region compared with [2] now is the whole Han-Kobayashi region. In addition, this construction not only removes the rate loss incurred by adding dummy messages to achieve security, but also change the original weak security condition in [2] to strong security. Then the equivocation rate for a collection of secret messages has also been evaluated, when the length of the message is finite or the information rate is high, our result provides a good approximation for bounding the worst case equivocation rate. Our results can be readily extended to the Gaussian interference channel with little efforts.
In this work, we derive new outer bounds for the two-user interference channel with confidential messages. An upper bound is found for the sum rate. When the interfering link of the first user is greater than 1, a new upper bound on 2R1+ R2is obtained by studying a special form of the three-user interference channel. The bounds are then compared with known bounds for the symmetric interference channel under strong interference regime. In particular, examples are presented to showcase for channel parameters where positive secrecy rates are known to be achievable, the new bounds improve upon the known outer bounds on the secrecy capacity region. It is shown that, in some cases, the 2R1+R2bound also improves the bound on the sum rate.
We studyinformation-theoretic securityfor discrete memorylessinterferenceandbroadcastchannels with independent confidential messages sent to two receivers. Confidential messages are transmitted to their respective receivers while ensuring mutual information-theoretic secrecy. That is, each receiver is kept in total ignorance with respect to the message intended for the other receiver. The secrecy level is measured by the equivocation rate at the eavesdropping receiver. In this paper, we present inner and outer bounds on secrecy capacity regions for these two communication systems. The derived outer bounds have an identical mutual information expression that applies to both channel models. The difference is in the input distributions over which the expression is optimized. The inner bound rate regions are achieved byrandom binningtechniques. For the broadcast channel, adouble-binningcoding scheme allows for both joint encoding and preserving of confidentiality. Furthermore, we show that, for a special case of the interference channel, referred to as theswitchchannel, derived bounds meet. Finally, we describe several transmission schemes for Gaussian interference channels and derive their achievable rate regions while ensuring mutual information-theoretic secrecy. An encoding scheme in which transmitters dedicate some of their power to createartificial noiseis proposed and shown to outperform both time-sharing and simple multiplexed transmission of the confidential messages.
We study information-theoretic security for discrete memoryless interference and broadcast channels with independent confidential messages sent to two receivers. Confidential messages are transmitted to their respective receivers with perfect secrecy. That is, each receiver is kept in total ignorance with respect to the message intended for the other receiver. The secrecy level is measured by the equivocation rate at the eavesdropping receiver. This approach was first introduced by Wyner in 1975 for the wiretap channel model. In this paper, we investigate the secrecy capacity region bounds for these two communication systems. The derived outer bounds have an identical mutual information expression that applies to the broadcast channel when one sender jointly encodes both messages and to the interference channel when two senders offer independent inputs to the channel. We consider a switch channel model which is a special case of the interference channel and show that the derived outer and inner bounds meet in this case. Finally, we focus on Gaussian interference channels with confidential messages and describe several transmission schemes and their achievable rate regions under the prefect secrecy requirement.
We introduce a secure communication setup of an interference channel whose transmitted signals are fed into interleavers. The interleavers apply random permutations to the signals, and the realizations of the permutations are made known to the receivers but not the transmitters. This communication setup can also model a situation in which the encoders are ignorant of the codebooks of one another, while the decoders are cognizant of the codebooks. We study the capacity region of a two-user secure Z-interference channel, and prove that an asymptotically optimal strategy of the interfered user is to use a constant composition random code. Consequently we establish the result that the capacity region of this channel, in the weak interference regime, is obtained by the Han-Kobayashi coding scheme. Further, we present an outer bound for the secure additive doubly weak interference channel, and an outer bound on the capacity region of the secure additive interference channel with mixed interference.
In this paper, capacity limits are explored for the Cognitive Radio Channel (CRC) with confidential messages. As an idealized information theoretic model for the cognitive radio, this channel includes two transmitters which send independent messages to their corresponding receivers such that one transmitter, i.e., the cognitive transmitter, has access non-causally to the message of the other transmitter, i.e., the primary transmitter. The message designated to each receiver is required to be kept confidential with respect to the other receiver. The secrecy level for each message is evaluated using the equivocation rate. Novel inner and outer bounds for the capacity-equivocation region are established. It is shown that these bounds coincide for some special cases. Specifically, the capacity-equivocation region is derived for a class of less-noisy CRCs and also a class of semi-deterministic CRCs. For the case where only the message of the cognitive transmitter is required to be kept confidential, the capacity-equivocation region is also established for the Gaussian CRC with weak interference.
This paper considers the two-user Gaussian interference channel in the presence of adversarial jammers. We first provide a general model including an arbitrary number of jammers, and show that its capacity region is equivalent to that of a simplified model in which the received jamming signal at each decoder is independent. Next, existing outer and inner bounds for two-user Gaussian interference channel are generalized for this simplified jamming model. We show that for certain problem parameters, precisely the same bounds hold, but with the noise variance increased by the received power of the jammer at each receiver. Thus, the jammers can do no better than to transmit Gaussian noise. For these problem parameters, this allows us to recover the half-bit theorem. In weak and strong interference regime, our inner bound matches the corresponding Han-Kobayashi bound with increased noise variance by the received power of the jammer, and even in strong interference we achieve the exact capacity. Furthermore, we determine the symmetric degrees of freedom where the signal-to-noise, interference-to-noise and jammer-to-noise ratios are all tend to infinity. Moreover, we show that, if the jammer has greater received power than the legitimate user, symmetrizability makes the capacity zero. The proof of the outer bound is straightforward, while the inner bound generalizes the Han-Kobayashi rate splitting scheme. As a novel aspect, the inner bound takes advantage of the common message acting as common randomness for the private message; hence, the jammer cannot symmetrize only the private codeword without being detected. This complication requires an extra condition on the signal power, so that in general our inner bound is not identical to the Han-Kobayashi bound. We also prove a new variation of the packing lemma that applies for multiple Gaussian codebooks in an adversarial setting.