Confidentiality of Age of Information against an Eavesdropper

In today's communication systems, across a wide variety of fields, timely and secure information delivery is crucial. This thesis addresses this challenge by introducing a novel framework, the Aging Value of Information (A-VoI), which measures how much information loses value over time. The model integrates entropy with the Age of Information (AoI) metric, by means of an exponential decaying function. Developing an objective function, we want to capture the trade-offs of two competing goals: getting fresh information to the intended receiver while keeping the information as stale as possible in the presence of an eavesdropper. This is achieved by determining the optimal transmission rates of two communication scenarios, the M/M/1 and M/M/1* queueing systems. Closed-form numerical analyses are shown to highlight that finding the best update strategies is key for secure real-time communications. This work underscores important aspects when building a communication system where both freshness and confidentiality are paramount.