A knowledge-based analysis of the blockchain protocol

Joseph Y. Halpern, Rafael Pass

Research output: Contribution to journalConference articlepeer-review


At the heart of the Bitcoin is a blockchain protocol, a protocol for achieving consensus on a public ledger that records bitcoin transactions. To the extent that a blockchain protocol is used for applications such as contract signing and making certain transactions (such as house sales) public, we need to understand what guarantees the protocol gives us in terms of agents' knowledge. Here, we provide a complete characterization of agent's knowledge when running a blockchain protocol using a variant of common knowledge that takes into account the fact that agents can enter and leave the system, it is not known which agents are in fact following the protocol (some agents may want to deviate if they can gain by doing so), and the fact that the guarantees provided by blockchain protocols are probabilistic. We then consider some scenarios involving contracts and show that this level of knowledge suffices for some scenarios, but not others.

Original languageEnglish
Pages (from-to)324-335
Number of pages12
JournalElectronic Proceedings in Theoretical Computer Science, EPTCS
StatePublished - 25 Jul 2017
Externally publishedYes
Event16th Conference on Theoretical Aspects of Rationality and Knowledge, TARK 2017 - Liverpool, United Kingdom
Duration: 24 Jul 201726 Jul 2017

All Science Journal Classification (ASJC) codes

  • Software


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