This paper investigates an information-theoretic model of secure semantic-aware communication. For this purpose, we consider the lossy joint source-channel coding (JSCC) of a memoryless semantic source transmitted over a memoryless wiretap channel. The source consists of two correlated parts that represent semantic and observed aspects of the information. Our model assumes separate fidelity and secrecy constraints on each source component and, in addition, encompasses two cases for the source output, in order to evaluate the performance gains if the encoder has an extended access to the source. Specifically, in Case 1, the encoder has direct access only to the samples from a single (observed) source component, while in Case 2 it has additional direct access to the samples of the underlying semantic information. We derive single-letter converse and achievability bounds on the rate-distortion-equivocation region. The converse bound explicitly contains rate-distortion functions, making it easy to evaluate, especially for some common distributions. The proposed achievability coding scheme involves novel stochastic superposition coding with two private parts to enable analysis of the equivocation for each source component, separately. Our results generalise some of the previously established source and source-channel coding problems. The general results are further specialised to Gaussian and Bernoulli sources transmitted over Gaussian and binary wiretap channels, respectively. The numerical evaluations illustrate the derived bounds for these distributions.

翻译：本文研究了安全语义感知通信的一个信息论模型。为此，我们考虑将无记忆语义信源经无记忆窃听信道传输时的有损联合信源信道编码（JSCC）。该信源由两个相关部分组成，分别代表信息的语义方面和观测方面。我们的模型对每个信源分量施加独立的保真度和保密性约束，此外，为了评估编码器在能够扩展访问信源时的性能增益，还涵盖了信源输出的两种情况。具体而言，在情况1中，编码器仅能直接访问单一（观测）信源分量的样本，而在情况2中，编码器还可额外直接访问底层语义信息的样本。我们推导了速率-失真-等价率区域的单字母下界和上界。下界明确包含速率-失真函数，使其易于评估，尤其适用于某些常见分布。所提出的可实现编码方案采用包含两个私有部分的新型随机叠加编码，以分别分析每个信源分量的等价率。我们的结果推广了先前一些已建立的信源和信源信道编码问题。进一步将一般结果特化至高斯信源和伯努利信源，并分别在高斯窃听信道和二进制窃听信道上传输。数值评估展示了这些分布下所推导的界限。