Beyond Security and Efficiency: On-Demand Ratcheting with Security Awareness

Secure asynchronous two-party communication applies ratcheting to strengthen privacy, in the presence of internal state exposures. Security with is provided two forms: forward security and post-compromise security. There have been several such secure protocols proposed last few years. However, they come a high cost.In this paper, we propose generic constructions favorable properties. Concretely, our first construction achieves awareness. It allows users detect non-persistent active attacks, determine which messages are not safe given potential leakage pattern, acknowledge for deliveries.In second construction, define hybrid system formed by combining protocols: typically, weakly “light” protocol strongly “heavy" protocol. The design goals are, first, let sender decide one use order obtain an efficient ratchet on demand; second, restore between honest participants case message loss or attack.We can apply any existing