This guidebook, the first of its kind, summarizes the state of the art in the field of epistemic gossip protocols. Gossip protocols are peer-to-peer communication protocols intended to maximize information dissemination while respecting network or transmission constraints. This comprehensive reference begins by presenting classical results on gossip protocols from networks and combinatorics from the 1970s and progresses through results in distributed computing up to the work on epistemic distributed gossip protocols of the past decade. In epistemic gossip protocols, agents make information-based choices to speed up information dissemination and allow smarter and more involved forms of distributed communication. Topics covered include various call semantics, reachability of secret distributions, dynamic gossip where secrets and numbers are exchanged, optimality, protocol knowledge, and higher-order epistemic goals. Featuring numerous exercises, this book from a lead researcher is an ideal resource for graduate students and researchers in logic, computer science, artificial intelligence, and cognitive science.

‘The author brings together a wealth of contributions to the literature on gossip. He is a master in making several hidden parameters in the simple question explicit, systematically grouping approaches together, and providing a formal analysis of the emerging problem settings and their solutions.’

Wiebe van der Hoek - University of Liverpool (Emeritus)

‘I consider this book an important contribution to computer science, in the sense that it employs a logical approach for rigorously formulating and proving facts about the gossiping communication paradigm. Besides its widespread use both in daily life and in computer communication, our scientific understanding of these protocols and their limits is quite poor. This book not only closes this gap for certain classes of models, and opens up ways for future work, but also explains why the author bothered with writing it: The second-to-last sentence, devoted to the role of a scientist in AI times, reads, ‘But nothing beats a live performance by Raphael Wallfisch, or playing Bach.’’

Ulrich Schmid - TU Wien, Austria