Epistemic Protocols for Distributed Gossiping

Abstract

Gossip protocols aim at arriving, by means of point-to-point or group communications, at a situation in which all the agents know each other's secrets. We consider distributed gossip protocols which are expressed by means of epistemic logic. We provide an operational semantics of such protocols and set up an appropriate framework to argue about their correctness. Then we analyze specific protocols for complete graphs and for directed rings.

On Decidability of a Logic of Gossips

“…Examples are protocols for the sequence transmission problem, such as the alternating bit protocol, studied in [7]. A more recent example are the distributed epistemic gossip protocols introduced in [3] and further studied in a slightly different setting in [1].…”

“…7 we show that it is also decidable to determine whether a given gossip protocol terminates. Then, in the final section, we list some related open problems and clarify the difference between the type of calls studied in [1,3].…”

“…As shown in [1], the formulation of distributed gossip protocols as knowledgebased programs considerably simplifies the task of their verification. The reason is that these protocols are strikingly simple in their syntax based on epistemic logic (though not semantics)-they are just parallel compositions of loops in which the agents repeatedly perform a call assuming the corresponding epistemic guard evaluates to true.…”

“…The reason is that these protocols are strikingly simple in their syntax based on epistemic logic (though not semantics)-they are just parallel compositions of loops in which the agents repeatedly perform a call assuming the corresponding epistemic guard evaluates to true. One issue ignored in [1] was the natural question: are these gossip protocols implementable?…”

“…In [1], as a follow up on [3], we also introduced distributed epistemic gossip protocols. We do not discuss them here and only mention that formulas of L are used in them as guards.…”