Some New Results on the GaussianWiretap Feedback Channel

Abstract

In this paper, the Gaussian wiretap feedback channel is revisited, and some new resultson its secrecy capacity are obtained. To be specific, first, we show that the Schalkwijk−Kailath (SK)feedback scheme, which achieves the secrecy capacity of the degraded Gaussian wiretap feedbackchannel, also achieves the secrecy capacity of the non-degraded Gaussian wiretap feedback channel.Second, applying the existing secret key-based feedback schemes to Gaussian wiretap feedbackchannels, we derive some new lower bounds on the secrecy capacities of these models. Finally,we compare the performances of the above feedback schemes in the degraded and non-degradedGaussian wiretap feedback channels and show which feedback scheme performs better for thesechannel models.

Keywords

• Gaussian wiretap channel
• noiseless feedback
• Schalkwijk–Kailath scheme
• secrecy capacity