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 underlaying 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：本文研究了一种安全语义感知通信的信息论模型。为此，我们考虑了在无记忆窃听信道上传输无记忆语义源的有损联合信源信道编码（JSCC）。该信源包含两个相关部分，分别代表信息的语义层面与观测层面。我们的模型对每个信源分量分别设定了保真度约束与保密性约束，并且为了评估编码器在扩展访问信源时的性能增益，进一步涵盖了两种信源输出情形。具体而言，在情形1中，编码器仅能直接访问单个（观测）信源分量的样本；而在情形2中，编码器还能额外直接访问底层语义信息的样本。我们推导了率-失真-泄露区域的单字母逆界与可达界。逆界明确包含率-失真函数，使其易于计算，尤其适用于某些常见分布。所提出的可达编码方案采用了一种新颖的随机叠加编码结构，通过两个私有部分实现对每个信源分量泄露程度的独立分析。我们的结果推广了先前建立的部分信源编码与信源信道编码问题。进一步将一般性结果具体应用于高斯信源与伯努利信源，分别通过高斯窃听信道与二进制窃听信道传输的案例。数值评估展示了这些分布下推导界的具体表现。