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Dealing with Unreliable Agents in Dynamic Gossip

Part of the Lecture Notes in Computer Science book series (LNTCS,volume 12569)


Gossip describes the spread of information throughout a network of agents. It investigates how agents, each starting with a unique secret, can efficiently make peer-to-peer calls so that ultimately everyone knows all secrets. In Dynamic Gossip, agents share phone numbers in addition to secrets, which allows the network to grow at run-time.

Most gossip protocols assume that all agents are reliable, but this is not given for many practical applications. We drop this assumption and study Dynamic Gossip with unreliable agents. The aim is then for agents to learn all secrets of the reliable agents and to identify the unreliable agents.

We show that with unreliable agents classic results on Dynamic Gossip no longer hold. Specifically, the Learn New Secrets protocol is no longer characterised by the same class of graphs, so-called sun graphs. In addition, we show that unreliable agents that do not initiate communication are harder to identify than agents that do. This has paradoxical consequences for measures against unreliability, for example to combat the spread of fake news in social networks.

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This work is based on the master’s thesis of the first author [5], supervised by Jan van Eijck. We thank Hans van Ditmarsch and the anonymous reviewers at the DaLí workshop for helpful feedback.

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Correspondence to Line van den Berg .

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van den Berg, L., Gattinger, M. (2020). Dealing with Unreliable Agents in Dynamic Gossip. In: Martins, M.A., Sedlár, I. (eds) Dynamic Logic. New Trends and Applications. DaLi 2020. Lecture Notes in Computer Science(), vol 12569. Springer, Cham.

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