Brief Announcement: On Using Null Messages in a Byzantine Setting

In reliable settings, null messages allow the transfer of information without explicit communication in cases of interest. We investigate the use of null messages in the much more challenging Byzantine model (without signatures). Different ways of using null messages are discussed. One of them, called a silent validation round, can provide processes with global information about all correct sites of the system, without any message exchange. As a case study, we consider optimizing the behavior in failure-free runs of protocols for the classic Byzantine Consensus problem.